diff --git a/bin/_mocha b/bin/_mocha
index 477b844f6f..45ec3cebce 100755
--- a/bin/_mocha
+++ b/bin/_mocha
@@ -73,6 +73,7 @@ program
   .option('-u, --ui <name>', 'specify user-interface (bdd|tdd|exports)', 'bdd')
   .option('-w, --watch', 'watch files for changes')
   .option('--check-leaks', 'check for global variable leaks')
+  .option('--full-trace', 'display the full stack trace')
   .option('--compilers <ext>:<module>,...', 'use the given module(s) to compile files', list, [])
   .option('--debug-brk', "enable node's debugger breaking on the first line")
   .option('--globals <names>', 'allow the given comma-delimited global [names]', list, [])
@@ -274,6 +275,10 @@ if (program.invert) mocha.invert();
 
 if (program.checkLeaks) mocha.checkLeaks();
 
+// --stack-trace
+
+if(program.fullTrace) mocha.fullTrace();
+
 // --growl
 
 if (program.growl) mocha.growl();
diff --git a/lib/mocha.js b/lib/mocha.js
index 61febc1ddb..3e29711a85 100644
--- a/lib/mocha.js
+++ b/lib/mocha.js
@@ -66,6 +66,7 @@ function image(name) {
  *   - `bail` bail on the first test failure
  *   - `slow` milliseconds to wait before considering a test slow
  *   - `ignoreLeaks` ignore global leaks
+ *   - `fullTrace` display the full stack-trace on failing
  *   - `grep` string or regexp to filter tests with
  *
  * @param {Object} options
@@ -265,6 +266,18 @@ Mocha.prototype.checkLeaks = function(){
   return this;
 };
 
+/**
+ * Display long stack-trace on failing
+ *
+ * @return {Mocha}
+ * @api public
+ */
+
+Mocha.prototype.fullTrace = function() {
+  this.options.fullStackTrace = true;
+  return this;
+};
+
 /**
  * Enable growl support.
  *
@@ -408,6 +421,7 @@ Mocha.prototype.run = function(fn){
   var runner = new exports.Runner(suite, options.delay);
   var reporter = new this._reporter(runner, options);
   runner.ignoreLeaks = false !== options.ignoreLeaks;
+  runner.fullStackTrace = options.fullStackTrace;
   runner.asyncOnly = options.asyncOnly;
   if (options.grep) runner.grep(options.grep, options.invert);
   if (options.globals) runner.globals(options.globals);
diff --git a/lib/runner.js b/lib/runner.js
index 7911896935..a555e8b69f 100644
--- a/lib/runner.js
+++ b/lib/runner.js
@@ -10,7 +10,8 @@ var EventEmitter = require('events').EventEmitter
   , filter = utils.filter
   , keys = utils.keys
   , type = utils.type
-  , stringify = utils.stringify;
+  , stringify = utils.stringify
+  , stackFilter = utils.stackTraceFilter();
 
 /**
  * Non-enumerable globals.
@@ -197,16 +198,18 @@ Runner.prototype.checkGlobals = function(test){
  * @api private
  */
 
-Runner.prototype.fail = function(test, err){
+Runner.prototype.fail = function(test, err) {
   ++this.failures;
   test.state = 'failed';
 
-  if ('string' == typeof err) {
-    err = new Error('the string "' + err + '" was thrown, throw an Error :)');
-  } else if (!(err instanceof Error)) {
+  if (!(err instanceof Error)) {
     err = new Error('the ' + type(err) + ' ' + stringify(err) + ' was thrown, throw an Error :)');
   }
 
+  err.stack = this.fullStackTrace
+    ? err.stack
+    : stackFilter(err.stack);
+
   this.emit('fail', test, err);
 };
 
diff --git a/lib/utils.js b/lib/utils.js
index bda5b8e84c..cb28b674e6 100644
--- a/lib/utils.js
+++ b/lib/utils.js
@@ -629,3 +629,68 @@ exports.getError = function(err) {
   return err || exports.undefinedError();
 };
 
+
+/**
+ * @summary
+ * This Filter based on `mocha-clean` module.(see: `github.com/rstacruz/mocha-clean`)
+ * @description
+ * When invoking this function you get a filter function that get the Error.stack as an input,
+ * and return a prettify output.
+ * (i.e: strip Mocha, node_modules, bower and componentJS from stack trace).
+ * @returns {Function}
+ */
+
+exports.stackTraceFilter = function() {
+  var slash = '/'
+    , is = typeof document === 'undefined'
+      ? { node: true }
+      : { browser: true }
+    , cwd = is.node
+      ? process.cwd() + slash
+      : location.href.replace(/\/[^\/]*$/, '/');
+
+  function isNodeModule (line) {
+    return (~line.indexOf('node_modules'));
+  }
+
+  function isMochaInternal (line) {
+    return (~line.indexOf('node_modules' + slash + 'mocha'))  ||
+      (~line.indexOf('components' + slash + 'mochajs'))       ||
+      (~line.indexOf('components' + slash + 'mocha'));
+  }
+
+  // node_modules, bower, componentJS
+  function isBrowserModule(line) {
+    return (~line.indexOf('node_modules')) ||
+      (~line.indexOf('components'));
+  }
+
+  function isNodeInternal (line) {
+    return (~line.indexOf('(timers.js:')) ||
+      (~line.indexOf('(events.js:'))      ||
+      (~line.indexOf('(node.js:'))        ||
+      (~line.indexOf('(module.js:'))      ||
+      (~line.indexOf('GeneratorFunctionPrototype.next (native)')) ||
+      false
+  }
+
+  return function(stack) {
+    stack = stack.split('\n');
+
+    stack = stack.reduce(function (list, line) {
+      if (is.node && (isNodeModule(line) ||
+        isMochaInternal(line) ||
+        isNodeInternal(line)))
+        return list;
+
+      if (is.browser && (isBrowserModule(line)))
+        return list;
+
+      // Clean up cwd(absolute)
+      list.push(line.replace(cwd, ''));
+      return list;
+    }, []);
+
+    return stack.join('\n');
+  }
+};
\ No newline at end of file
diff --git a/mocha.js b/mocha.js
index e355cd9da6..bf761a7834 100644
--- a/mocha.js
+++ b/mocha.js
@@ -1470,6 +1470,7 @@ function image(name) {
  *   - `bail` bail on the first test failure
  *   - `slow` milliseconds to wait before considering a test slow
  *   - `ignoreLeaks` ignore global leaks
+ *   - `fullTrace` display the full stack-trace on failing
  *   - `grep` string or regexp to filter tests with
  *
  * @param {Object} options
@@ -1669,6 +1670,18 @@ Mocha.prototype.checkLeaks = function(){
   return this;
 };
 
+/**
+ * Display long stack-trace on failing
+ *
+ * @return {Mocha}
+ * @api public
+ */
+
+Mocha.prototype.fullTrace = function() {
+  this.options.fullStackTrace = true;
+  return this;
+};
+
 /**
  * Enable growl support.
  *
@@ -1812,6 +1825,7 @@ Mocha.prototype.run = function(fn){
   var runner = new exports.Runner(suite, options.delay);
   var reporter = new this._reporter(runner, options);
   runner.ignoreLeaks = false !== options.ignoreLeaks;
+  runner.fullStackTrace = options.fullStackTrace;
   runner.asyncOnly = options.asyncOnly;
   if (options.grep) runner.grep(options.grep, options.invert);
   if (options.globals) runner.globals(options.globals);
@@ -4560,7 +4574,8 @@ var EventEmitter = require('browser/events').EventEmitter
   , filter = utils.filter
   , keys = utils.keys
   , type = utils.type
-  , stringify = utils.stringify;
+  , stringify = utils.stringify
+  , stackFilter = utils.stackTraceFilter();
 
 /**
  * Non-enumerable globals.
@@ -4751,16 +4766,18 @@ Runner.prototype.checkGlobals = function(test){
  * @api private
  */
 
-Runner.prototype.fail = function(test, err){
+Runner.prototype.fail = function(test, err) {
   ++this.failures;
   test.state = 'failed';
 
-  if ('string' == typeof err) {
-    err = new Error('the string "' + err + '" was thrown, throw an Error :)');
-  } else if (!(err instanceof Error)) {
+  if (!(err instanceof Error)) {
     err = new Error('the ' + type(err) + ' ' + stringify(err) + ' was thrown, throw an Error :)');
   }
 
+  err.stack = this.fullStackTrace
+    ? err.stack
+    : stackFilter(err.stack);
+
   this.emit('fail', test, err);
 };
 
@@ -6304,6 +6321,70 @@ exports.getError = function(err) {
 };
 
 
+/**
+ * @summary
+ * This Filter based on `mocha-clean` module.(see: `github.com/rstacruz/mocha-clean`)
+ * @description
+ * When invoking this function you get a filter function that get the Error.stack as an input,
+ * and return a prettify output.
+ * (i.e: strip Mocha, node_modules, bower and componentJS from stack trace).
+ * @returns {Function}
+ */
+
+exports.stackTraceFilter = function() {
+  var slash = '/'
+    , is = typeof document === 'undefined'
+      ? { node: true }
+      : { browser: true }
+    , cwd = is.node
+      ? process.cwd() + slash
+      : location.href.replace(/\/[^\/]*$/, '/');
+
+  function isNodeModule (line) {
+    return (~line.indexOf('node_modules'));
+  }
+
+  function isMochaInternal (line) {
+    return (~line.indexOf('node_modules' + slash + 'mocha'))  ||
+      (~line.indexOf('components' + slash + 'mochajs'))       ||
+      (~line.indexOf('components' + slash + 'mocha'));
+  }
+
+  // node_modules, bower, componentJS
+  function isBrowserModule(line) {
+    return (~line.indexOf('node_modules')) ||
+      (~line.indexOf('components'));
+  }
+
+  function isNodeInternal (line) {
+    return (~line.indexOf('(timers.js:')) ||
+      (~line.indexOf('(events.js:'))      ||
+      (~line.indexOf('(node.js:'))        ||
+      (~line.indexOf('(module.js:'))      ||
+      (~line.indexOf('GeneratorFunctionPrototype.next (native)')) ||
+      false
+  }
+
+  return function(stack) {
+    stack = stack.split('\n');
+
+    stack = stack.reduce(function (list, line) {
+      if (is.node && (isNodeModule(line) ||
+        isMochaInternal(line) ||
+        isNodeInternal(line)))
+        return list;
+
+      if (is.browser && (isBrowserModule(line)))
+        return list;
+
+      // Clean up cwd(absolute)
+      list.push(line.replace(cwd, ''));
+      return list;
+    }, []);
+
+    return stack.join('\n');
+  }
+};
 }); // module: utils.js
 // The global object is "self" in Web Workers.
 var global = (function() { return this; })();
diff --git a/test/browser/stack-trace.html b/test/browser/stack-trace.html
new file mode 100644
index 0000000000..0f267dab98
--- /dev/null
+++ b/test/browser/stack-trace.html
@@ -0,0 +1,24 @@
+<html>
+<head>
+    <title>Mocha</title>
+    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <link rel="stylesheet" href="../../mocha.css" />
+    <script src="../../mocha.js"></script>
+    <script>mocha.setup('bdd')</script>
+    <script>
+        function assert(expr, err) {
+            if (!expr) throw err;
+        }
+    </script>
+    <script src="stack-trace.js"></script>
+    <script>
+        onload = function() {
+            mocha.run();
+        };
+    </script>
+</head>
+<body>
+<div id="mocha"></div>
+</body>
+</html>
diff --git a/test/browser/stack-trace.js b/test/browser/stack-trace.js
new file mode 100644
index 0000000000..b39944db09
--- /dev/null
+++ b/test/browser/stack-trace.js
@@ -0,0 +1,20 @@
+'use strict';
+describe('Stack trace', function() {
+  it('should prettify the stack-trace', function() {
+    var err = new Error();
+    // We do this fake stack-trace because we under development,
+    // and our root isn't `node_modules`, `bower` or `components`
+    err.stack = ['Error: failed'
+      , 'at assert (stack-trace.html:11:30)'
+      , 'at Context.<anonymous> (stack-trace.js:5:5)'
+      , 'at callFn (http://localhost:63342/node_modules/mocha.js:4546:21)'
+      , 'at Test.require.register.Runnable.run (http://localhost:63342/node_modules/mocha.js:4539:7)'
+      , 'at Runner.require.register.Runner.runTest (http://localhost:63342/node_modules/mocha.js:4958:10)'
+      , 'at http://localhost:63342/bower_components/mocha.js:5041:12'
+      , 'at next (http://localhost:63342/bower_components/mocha.js:4883:14)'
+      , 'at http://localhost:63342/bower_components/mocha.js:4893:7'
+      , 'at next (http://localhost:63342/bower_components/mocha.js:4828:23)'
+      , 'at http://localhost:63342/bower_components/mocha.js:4860:5'].join('\n');
+    assert(false, err);
+  });
+});
\ No newline at end of file
diff --git a/test/runner.js b/test/runner.js
index 89cb8216b4..a2ce512514 100644
--- a/test/runner.js
+++ b/test/runner.js
@@ -290,5 +290,51 @@ describe('Runner', function(){
       runner.failHook(hook, err);
       done();
     })
-  })
-})
+  });
+
+  describe('stackTrace', function() {
+    var stack = [ 'AssertionError: foo bar'
+      , 'at EventEmitter.<anonymous> (/usr/local/dev/test.js:16:12)'
+      , 'at Context.<anonymous> (/usr/local/dev/test.js:19:5)'
+      , 'Test.Runnable.run (/usr/local/lib/node_modules/mocha/lib/runnable.js:244:7)'
+      , 'Runner.runTest (/usr/local/lib/node_modules/mocha/lib/runner.js:374:10)'
+      , '/usr/local/lib/node_modules/mocha/lib/runner.js:452:12'
+      , 'next (/usr/local/lib/node_modules/mocha/lib/runner.js:299:14)'
+      , '/usr/local/lib/node_modules/mocha/lib/runner.js:309:7'
+      , 'next (/usr/local/lib/node_modules/mocha/lib/runner.js:248:23)'
+      , 'Immediate._onImmediate (/usr/local/lib/node_modules/mocha/lib/runner.js:276:5)'
+      , 'at processImmediate [as _immediateCallback] (timers.js:321:17)'];
+
+    describe('shortStackTrace', function() {
+      it('should prettify the stack-trace', function(done) {
+        var hook = {},
+            err = new Error();
+        // Fake stack-trace
+        err.stack = stack.join('\n');
+
+        runner.on('fail', function(hook, err){
+          err.stack.should.equal(stack.slice(0,3).join('\n'));
+          done();
+        });
+        runner.failHook(hook, err);
+      });
+    });
+
+    describe('longStackTrace', function() {
+      it('should display the full stack-trace', function(done) {
+        var hook = {},
+            err = new Error();
+        // Fake stack-trace
+        err.stack = stack.join('\n');
+        // Add --stack-trace option
+        runner.fullStackTrace = true;
+
+        runner.on('fail', function(hook, err){
+          err.stack.should.equal(stack.join('\n'));
+          done();
+        });
+        runner.failHook(hook, err);
+      });
+    });
+  });
+});
diff --git a/test/utils.js b/test/utils.js
index f60b42fc9f..780d8c324c 100644
--- a/test/utils.js
+++ b/test/utils.js
@@ -64,4 +64,81 @@ describe('utils', function() {
       });
     })
   });
+
+  describe('.stackTraceFilter()', function() {
+    describe('on node', function() {
+      var filter = utils.stackTraceFilter();
+      it('should get a stack-trace as a string and prettify it', function() {
+        var stack = [ 'AssertionError: foo bar'
+            , 'at EventEmitter.<anonymous> (/usr/local/dev/test.js:16:12)'
+            , 'at Context.<anonymous> (/usr/local/dev/test.js:19:5)'
+            , 'Test.Runnable.run (/usr/local/lib/node_modules/mocha/lib/runnable.js:244:7)'
+            , 'Runner.runTest (/usr/local/lib/node_modules/mocha/lib/runner.js:374:10)'
+            , '/usr/local/lib/node_modules/mocha/lib/runner.js:452:12'
+            , 'next (/usr/local/lib/node_modules/mocha/lib/runner.js:299:14)'
+            , '/usr/local/lib/node_modules/mocha/lib/runner.js:309:7'
+            , 'next (/usr/local/lib/node_modules/mocha/lib/runner.js:248:23)'
+            , 'Immediate._onImmediate (/usr/local/lib/node_modules/mocha/lib/runner.js:276:5)'
+            , 'at processImmediate [as _immediateCallback] (timers.js:321:17)'];
+        filter(stack.join('\n')).should.equal(stack.slice(0,3).join('\n'));
+
+        stack = [ 'AssertionError: bar baz'
+          , 'at /usr/local/dev/some-test-file.js:25:8'
+          , 'at tryCatcher (/usr/local/dev/own/tmp/node_modules/bluebird/js/main/util.js:24:31)'
+          , 'at Promise._resolveFromResolver (/usr/local/dev/own/tmp/node_modules/bluebird/js/main/promise.js:439:31)'
+          , 'at new Promise (/usr/local/dev/own/tmp/node_modules/bluebird/js/main/promise.js:53:37)'
+          , 'at yourFunction (/usr/local/dev/own/tmp/test1.js:24:13)'
+          , 'at Context.<anonymous> (/usr/local/dev/some-test-file:30:4)'
+          , 'Test.Runnable.run (/usr/local/lib/node_modules/mocha/lib/runnable.js:218:15)'
+          , 'next (/usr/local/lib/node_modules/mocha/lib/runner.js:248:23)'
+          , 'Immediate._onImmediate (/usr/local/lib/node_modules/mocha/lib/runner.js:276:5)'
+          , 'at processImmediate [as _immediateCallback] (timers.js:321:17)'];
+        filter(stack.join('\n')).should.equal(stack.slice(0,2).concat(stack.slice(5,7)).join('\n'));
+      });
+
+      it('should ignore bower and components files', function() {
+        var stack = ['Error: failed'
+          , 'at assert (index.html:11:26)'
+          , 'at Context.<anonymous> (test.js:17:18)'
+          , 'at bower_components/should/should.js:4827:7'
+          , 'at next (file:///.../bower_components/should/should.js:4766:23)'
+          , 'at components/should/5.0.0/should.js:4827:7'
+          , 'at next (file:///.../components/should/5.0.0/should.js:4766:23)'
+          , 'at file:///.../bower_components/mocha/mocha.js:4794:5'
+          , 'at timeslice (.../components/mocha/mocha.js:6218:27)'
+          , 'at Test.require.register.Runnable.run (file:///.../components/mochajs/mocha/2.1.0/mocha.js:4463:15)'
+          , 'at Runner.require.register.Runner.runTest (file:///.../components/mochajs/mocha/2.1.0/mocha.js:4892:10)'
+          , 'at file:///.../components/mochajs/mocha/2.1.0/mocha.js:4970:12'
+          , 'at next (file:///.../components/mochajs/mocha/2.1.0/mocha.js:4817:14)'];
+        filter(stack.join('\n')).should.equal(stack.slice(0,7).join('\n'));
+      });
+    });
+
+    describe('on browser', function() {
+      var filter;
+      before(function() {
+        global.document = true;
+        global.location = { href: 'localhost:3000/foo/bar/index.html' };
+        filter = utils.stackTraceFilter();
+      });
+      it('should strip out bower and components too', function() {
+        var stack = ['Error: failed'
+          , 'at assert (index.html:11:26)'
+          , 'at Context.<anonymous> (test.js:17:18)'
+          , 'at bower_components/should/should.js:4827:7'
+          , 'at next (localhost:3000/foo/bar/bower_components/should/should.js:4766:23)'
+          , 'at components/should/5.0.0/should.js:4827:7'
+          , 'at next (localhost:3000/foo/bar/components/should/5.0.0/should.js:4766:23)'
+          , 'at Runner.require.register.Runner.runTest (localhost:3000/foo/bar/node_modules/mocha.js:4892:10)'
+          , 'at localhost:3000/foo/bar/node_modules/mocha.js:4970:12'
+          , 'at next (localhost:3000/foo/bar/node_modules/mocha.js:4817:14)'];
+        filter(stack.join('\n')).should.equal(stack.slice(0,3).join('\n'));
+      });
+
+      after(function() {
+        delete global.document;
+        delete global.location;
+      });
+    });
+  });
 });