diff --git a/packages/plugin-ext/src/hosted/node/hosted-plugin-process.ts b/packages/plugin-ext/src/hosted/node/hosted-plugin-process.ts
index e8cda321abfe3..84646da0cc7c0 100644
--- a/packages/plugin-ext/src/hosted/node/hosted-plugin-process.ts
+++ b/packages/plugin-ext/src/hosted/node/hosted-plugin-process.ts
@@ -17,7 +17,7 @@
 import * as path from 'path';
 import * as cp from 'child_process';
 import { injectable, inject, named } from 'inversify';
-import { ILogger, ConnectionErrorHandler, ContributionProvider } from '@theia/core/lib/common';
+import { ILogger, ConnectionErrorHandler, ContributionProvider, isWindows } from '@theia/core/lib/common';
 import { Emitter } from '@theia/core/lib/common/event';
 import { createIpcEnv } from '@theia/core/lib/node/messaging/ipc-protocol';
 import { HostedPluginClient, ServerPluginRunner, PluginMetadata, PluginHostEnvironmentVariable } from '../../common/plugin-protocol';
@@ -25,6 +25,7 @@ import { RPCProtocolImpl } from '../../api/rpc-protocol';
 import { MAIN_RPC_CONTEXT } from '../../api/plugin-api';
 import { HostedPluginCliContribution } from './hosted-plugin-cli-contribution';
 import {HostedPluginProcessesCache} from './hosted-plugin-processes-cache';
+const psTree = require('ps-tree');
 
 export interface IPCConnectionOptions {
     readonly serverName: string;
@@ -122,11 +123,26 @@ export class HostedPluginProcess implements ServerPluginRunner {
         const hostedPluginManager = rpc.getProxy(MAIN_RPC_CONTEXT.HOSTED_PLUGIN_MANAGER_EXT);
         hostedPluginManager.$stopPlugin('').then(() => {
             emitter.dispose();
-            cp.kill();
+            this.killProcessTree(cp);
         });
 
     }
 
+    private killProcessTree(parentProcess: cp.ChildProcess): void {
+        parentProcess.disconnect();
+        const parentPid = parentProcess.pid;
+        if (isWindows) {
+            cp.spawn('taskkill', ['/F', '/T', '/PID', parentPid.toString()]);
+        } else {
+            // tslint:disable-next-line:no-any
+            psTree(parentPid, (err: Error, children: Array<any>) => {
+                parentProcess.kill();
+                // tslint:disable-next-line:no-any
+                cp.spawn('kill', children.map((p: any) => p.PID));
+            });
+        }
+    }
+
     public runPluginServer(): void {
         if (this.childProcess) {
             this.terminatePluginServer();