diff --git a/rse/plugins/org.eclipse.rse.subsystems.files.core/src/org/eclipse/rse/subsystems/files/core/servicesubsystem/FileServiceSubSystem.java b/rse/plugins/org.eclipse.rse.subsystems.files.core/src/org/eclipse/rse/subsystems/files/core/servicesubsystem/FileServiceSubSystem.java
index b4491e6f5b1..3068a3700c8 100644
--- a/rse/plugins/org.eclipse.rse.subsystems.files.core/src/org/eclipse/rse/subsystems/files/core/servicesubsystem/FileServiceSubSystem.java
+++ b/rse/plugins/org.eclipse.rse.subsystems.files.core/src/org/eclipse/rse/subsystems/files/core/servicesubsystem/FileServiceSubSystem.java
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2006, 2010 IBM Corporation and others.
+ * Copyright (c) 2006, 2011 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
@@ -46,6 +46,7 @@
  * David McKnight   (IBM)        - [272882] [api] Handle exceptions in IService.initService()
  * David McKnight   (IBM)        - [244041] [files] Renaming a file looses Encoding property
  * David McKnight   (IBM)        - [320713] [dstore] xml file transfer error on zOS
+ * David McKnight   (IBM)        - [368454] provide thread safety for cachedRemoteFiles hashmap
  *******************************************************************************/
 
 package org.eclipse.rse.subsystems.files.core.servicesubsystem;
@@ -1154,7 +1155,9 @@ public class FileServiceSubSystem extends RemoteFileSubSystem implements IFileSe
 			IHost host = getHost();
 			IFileServiceSubSystemConfiguration config = (IFileServiceSubSystemConfiguration) newConfig;
 			// file subsystem specific bits
-			_cachedRemoteFiles.clear();
+			synchronized (_cachedRemoteFiles){
+				_cachedRemoteFiles.clear();
+			}
 			_languageUtilityFactory = null;
 			setFileService(config.getFileService(host));
 			setHostFileToRemoteFileAdapter(config.getHostFileAdapter());
diff --git a/rse/plugins/org.eclipse.rse.subsystems.files.core/src/org/eclipse/rse/subsystems/files/core/subsystems/RemoteFileSubSystem.java b/rse/plugins/org.eclipse.rse.subsystems.files.core/src/org/eclipse/rse/subsystems/files/core/subsystems/RemoteFileSubSystem.java
index c8d253897d3..c1c6f566b7b 100644
--- a/rse/plugins/org.eclipse.rse.subsystems.files.core/src/org/eclipse/rse/subsystems/files/core/subsystems/RemoteFileSubSystem.java
+++ b/rse/plugins/org.eclipse.rse.subsystems.files.core/src/org/eclipse/rse/subsystems/files/core/subsystems/RemoteFileSubSystem.java
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2002, 2009 IBM Corporation and others.
+ * Copyright (c) 2002, 2011 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
@@ -29,6 +29,7 @@
  * Martin Oberhuber (Wind River) - [226574][api] Add ISubSystemConfiguration#supportsEncoding()
  * David McKnight (IBM) 		 - [225747] [dstore] Trying to connect to an "Offline" system throws an NPE
  * David McKnight   (IBM)        - [272882] [api] Handle exceptions in IService.initService()
+ * David McKnight   (IBM)        - [368454] provide thread safety for cachedRemoteFiles hashmap
  *******************************************************************************/
 
 package org.eclipse.rse.subsystems.files.core.subsystems;
@@ -1271,35 +1272,43 @@ public abstract class RemoteFileSubSystem extends SubSystem implements IRemoteFi
 	 */
 	public void cacheRemoteFile(IRemoteFile file, String path)
 	{
-
-		if (_cachedRemoteFiles.containsKey(path))
-		{
-			IRemoteFile oldFile = (IRemoteFile)_cachedRemoteFiles.remove(path);
-			if (oldFile == file)
-			{
+		boolean containsKey = false;
+		synchronized (_cachedRemoteFiles){
+			containsKey = _cachedRemoteFiles.containsKey(path);
+		}
+		if (containsKey){
+			IRemoteFile oldFile = null;
+			synchronized (_cachedRemoteFiles){
+				oldFile = (IRemoteFile)_cachedRemoteFiles.remove(path);
+			}
+			if (oldFile == file){
 				// already cached - recache
-				_cachedRemoteFiles.put(path, file);
+				synchronized (_cachedRemoteFiles){
+					_cachedRemoteFiles.put(path, file);
+				}
 				return;
 			}
-
+	
 			// replace file under parent
 			if (oldFile instanceof RemoteFile) {
 				RemoteFile roldFile = (RemoteFile)oldFile;
-				if (roldFile._parentFile != null) // prevent parent query from bug #196664
-				{
+				if (roldFile._parentFile != null){ // prevent parent query from bug #196664
 					roldFile._parentFile.replaceContent(oldFile, file);
 				}
 			}
 			else if (oldFile != null && oldFile.getParentRemoteFile() != null) {
 				oldFile.getParentRemoteFile().replaceContent(oldFile, file);
 			}
-
+	
 			// preserve persistent information from old file to new
-			if (oldFile != null)
+			if (oldFile != null){
 				oldFile.copyContentsTo(file);
-
+			}
+		}
+		
+		synchronized (_cachedRemoteFiles){
+			_cachedRemoteFiles.put(path, file);
 		}
-		_cachedRemoteFiles.put(path, file);
 	}
 
 	/**
@@ -1321,18 +1330,19 @@ public abstract class RemoteFileSubSystem extends SubSystem implements IRemoteFi
 	 */
 	public IRemoteFile getCachedRemoteFile(String path)
 	{
-		if (_cachedRemoteFiles.size() > 0)
-		{
-	     path = path.replaceAll("//", "/"); //$NON-NLS-1$ //$NON-NLS-2$
-	     if (path.endsWith("\\") || (path.endsWith("/") && path.length() > 1)) //$NON-NLS-1$ //$NON-NLS-2$
-	     {
-	         path = path.substring(0, path.length() - 1);
-	     }
-		  if (_cachedRemoteFiles.containsKey(path))
-		  {
-		      {return (IRemoteFile)_cachedRemoteFiles.get(path);}
-		  }
-
+		synchronized (_cachedRemoteFiles){
+			if (_cachedRemoteFiles.size() > 0)
+			{
+		     path = path.replaceAll("//", "/"); //$NON-NLS-1$ //$NON-NLS-2$
+		     if (path.endsWith("\\") || (path.endsWith("/") && path.length() > 1)) //$NON-NLS-1$ //$NON-NLS-2$
+		     {
+		         path = path.substring(0, path.length() - 1);
+		     }
+			  if (_cachedRemoteFiles.containsKey(path))
+			  {
+			      {return (IRemoteFile)_cachedRemoteFiles.get(path);}
+			  }
+			}
 		}
 		return null;
 	}
@@ -1356,7 +1366,10 @@ public abstract class RemoteFileSubSystem extends SubSystem implements IRemoteFi
 			//If getContents() is implemented correctly, no matches should be removed
 			String prefix = file.getAbsolutePath() + file.getSeparator();
 			//Clone the hashMap in order to avoid ConcurrentModificationException in the iterator
-			HashMap tmpMap = (HashMap)_cachedRemoteFiles.clone();
+			HashMap tmpMap = null;
+			synchronized (_cachedRemoteFiles){
+				tmpMap = (HashMap)_cachedRemoteFiles.clone();
+			}
 			Iterator it = tmpMap.keySet().iterator();
 			while (it.hasNext()) {
 				String remotePath = (String)it.next();
@@ -1367,13 +1380,15 @@ public abstract class RemoteFileSubSystem extends SubSystem implements IRemoteFi
 				}
 			}
 
-			_cachedRemoteFiles.remove(file.getAbsolutePath());
+			removeCachedRemoteFile(file.getAbsolutePath());			
 		}
 	}
 
 	protected void removeCachedRemoteFile(String path)
 	{
-		_cachedRemoteFiles.remove(path);
+		synchronized (_cachedRemoteFiles){
+			_cachedRemoteFiles.remove(path);
+		}
 	}
 
 
@@ -1382,7 +1397,9 @@ public abstract class RemoteFileSubSystem extends SubSystem implements IRemoteFi
 		switch (e.getState())
 		{
 			case CommunicationsEvent.AFTER_DISCONNECT :
-				_cachedRemoteFiles.clear();
+				synchronized (_cachedRemoteFiles){
+					_cachedRemoteFiles.clear();
+				}
 				// DKM - taking this out because it causes an exception when the event occurs in Modal Context
 				//ISystemRegistry sr = RSECorePlugin.getTheSystemRegistry();
 				//sr.connectedStatusChange(this, false, true, true);