diff --git a/src/System.Data.OleDb/src/OleDbConnection.cs b/src/System.Data.OleDb/src/OleDbConnection.cs
index d337db4d4fcc..3a9a17c7e897 100644
--- a/src/System.Data.OleDb/src/OleDbConnection.cs
+++ b/src/System.Data.OleDb/src/OleDbConnection.cs
@@ -515,12 +515,6 @@ internal void OnInfoMessage(UnsafeNativeMethods.IErrorInfo errorInfo, OleDbHResu
                     ADP.TraceExceptionWithoutRethrow(e);
                 }
             }
-#if DEBUG
-            else
-            {
-                OleDbException exception = OleDbException.CreateException(errorInfo, errorCode, null);
-            }
-#endif
         }
 
         public override void Open()
diff --git a/src/System.Data.OleDb/src/OleDbConnectionInternal.cs b/src/System.Data.OleDb/src/OleDbConnectionInternal.cs
index 6cabd022ebb9..ebd13dcea280 100644
--- a/src/System.Data.OleDb/src/OleDbConnectionInternal.cs
+++ b/src/System.Data.OleDb/src/OleDbConnectionInternal.cs
@@ -321,7 +321,6 @@ public override void Dispose()
 
         public override void EnlistTransaction(SysTx.Transaction transaction)
         {
-            OleDbConnection outerConnection = Connection;
             if (null != LocalTransaction)
             {
                 throw ADP.LocalTransactionPresent();
@@ -821,8 +820,6 @@ internal OleDbTransaction ValidateTransaction(OleDbTransaction transaction, stri
 
         internal Dictionary<string, OleDbPropertyInfo> GetPropertyInfo(Guid[] propertySets)
         {
-            bool isopen = HasSession;
-            OleDbConnectionString constr = ConnectionString;
             Dictionary<string, OleDbPropertyInfo> properties = null;
 
             if (null == propertySets)
diff --git a/src/System.Data.OleDb/src/OleDbDataAdapter.cs b/src/System.Data.OleDb/src/OleDbDataAdapter.cs
index cdd5c63432e4..e50b7b50b44f 100644
--- a/src/System.Data.OleDb/src/OleDbDataAdapter.cs
+++ b/src/System.Data.OleDb/src/OleDbDataAdapter.cs
@@ -262,10 +262,6 @@ record = (adodb as UnsafeNativeMethods.ADORecordConstruction);
                                 UnsafeNativeMethods.GetErrorInfo(0, out errorInfo);
 
                                 string message = string.Empty;
-                                if (null != errorInfo)
-                                {
-                                    OleDbHResult hresult = ODB.GetErrorDescription(errorInfo, hr, out message);
-                                }
                                 throw new COMException(message, (int)hr);
                             }
                             break;
@@ -436,10 +432,6 @@ private void FillClose(bool isrecordset, object value)
                 UnsafeNativeMethods.IErrorInfo errorInfo = null;
                 UnsafeNativeMethods.GetErrorInfo(0, out errorInfo);
                 string message = string.Empty;
-                if (null != errorInfo)
-                {
-                    OleDbHResult hresult = ODB.GetErrorDescription(errorInfo, hr, out message);
-                }
                 throw new COMException(message, (int)hr);
             }
         }
diff --git a/src/System.Data.OleDb/src/OleDbDataReader.cs b/src/System.Data.OleDb/src/OleDbDataReader.cs
index 1359e81b4549..5ee968c3c07a 100644
--- a/src/System.Data.OleDb/src/OleDbDataReader.cs
+++ b/src/System.Data.OleDb/src/OleDbDataReader.cs
@@ -1166,7 +1166,7 @@ public override int GetValues(object[] values)
             {
                 throw ADP.ArgumentNull("values");
             }
-            MetaData info = DoValueCheck(0);
+            DoValueCheck(0);
             int count = Math.Min(values.Length, _visibleFieldCount);
             for (int i = 0; (i < _metadata.Length) && (i < count); ++i)
             {
@@ -2163,7 +2163,6 @@ private void AppendSchemaUniqueIndexAsKey(Hashtable baseColumnNames, object[] re
                     {
                         bool isPKey = (!dataRow.IsNull(pkeyColumn, DataRowVersion.Default) && (bool)dataRow[pkeyColumn, DataRowVersion.Default]);
                         bool isUniq = (!dataRow.IsNull(uniqCOlumn, DataRowVersion.Default) && (bool)dataRow[uniqCOlumn, DataRowVersion.Default]);
-                        bool nullsVal = (null != nulls) && (dataRow.IsNull(nulls, DataRowVersion.Default) || (ODB.DBPROPVAL_IN_ALLOWNULL == Convert.ToInt32(dataRow[nulls, DataRowVersion.Default], CultureInfo.InvariantCulture)));
 
                         if (isPKey || isUniq)
                         {
diff --git a/src/System.Data.OleDb/src/OleDbTransaction.cs b/src/System.Data.OleDb/src/OleDbTransaction.cs
index 2c05339f9a88..0db6714d5477 100644
--- a/src/System.Data.OleDb/src/OleDbTransaction.cs
+++ b/src/System.Data.OleDb/src/OleDbTransaction.cs
@@ -108,7 +108,7 @@ protected override bool ReleaseHandle()
             {
                 if (_mustComplete && (IntPtr.Zero != base.handle))
                 {
-                    OleDbHResult hr = (OleDbHResult)NativeOledbWrapper.ITransactionAbort(base.handle);
+                    NativeOledbWrapper.ITransactionAbort(base.handle);
                     _mustComplete = false;
                 }
                 return base.ReleaseHandle();
diff --git a/src/System.Data.OleDb/src/RowBinding.cs b/src/System.Data.OleDb/src/RowBinding.cs
index 6b0f7629aa4f..9bd1c700019d 100644
--- a/src/System.Data.OleDb/src/RowBinding.cs
+++ b/src/System.Data.OleDb/src/RowBinding.cs
@@ -478,8 +478,7 @@ private static void FreeChapter(IntPtr buffer, int valueOffset, object iaccessor
             IntPtr chapter = SafeNativeMethods.InterlockedExchangePointer(ADP.IntPtrOffset(buffer, valueOffset), ADP.PtrZero);
             if (ODB.DB_NULL_HCHAPTER != chapter)
             {
-                int refCount;
-                OleDbHResult hr = chapteredRowset.ReleaseChapter(chapter, out refCount);
+                chapteredRowset.ReleaseChapter(chapter, out _);
             }
         }
 
diff --git a/src/System.Data.OleDb/src/SafeHandles.cs b/src/System.Data.OleDb/src/SafeHandles.cs
index cf4872210f9f..727d3d4ada8c 100644
--- a/src/System.Data.OleDb/src/SafeHandles.cs
+++ b/src/System.Data.OleDb/src/SafeHandles.cs
@@ -160,7 +160,7 @@ protected override bool ReleaseHandle()
 
             if ((IntPtr.Zero != base.handle) && (IntPtr.Zero != chapter))
             {
-                OleDbHResult hr = (OleDbHResult)NativeOledbWrapper.IChapteredRowsetReleaseChapter(base.handle, chapter);
+                NativeOledbWrapper.IChapteredRowsetReleaseChapter(base.handle, chapter);
             }
             return base.ReleaseHandle();
         }