I have a JunitTest case that is testing some client server code. I create a separate threads to emulate the client and the server and expect to see operations interspersed. However they seemed to run sequentially. Running with debug on in eclipse, it looks as so all the Thread.run() calls are stacked in the same (main) thread. I would have expected that after the new Thread(new myRunnabled()).run a new thread to appear in the debug window. Here's is the stack trace from the main thread and its evident that after the run() methid is called the runnable is executing in the main thread.