My guess is that the problem stems from your thread trying to invoke EntityManager.merge(). Since your thread probably doesn't do any transaction management you are getting that TransactionRequiredException. Before you try to fix that though, consider that you probably shouldn't be spawning your own threads inside the app server. I would try to find a different way that doesn't involve spawning any threads. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4064762#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...