Actually the whole picture is: - Seam should only require JTA if you use TransactionalSeamPhaseListener because then Seam will call JTA to begin and end transactions - Seam will start whatever EntityManagerFactory you configure in components.xml for you - The issue is that you also want Seam-managed persistence contexts, so you let Seam have that EMF and open and close EntityManagers for you. This doesn't make much sense if you do not also let Seam handle transactions for you. So conclusion: Seam-managed persistence contexts require a JTA runtime because the transaction handler is using the standard JTA interfaces. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4036257#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...