After all I was not able to deploy my EAR with the provided EJB jars successfully. But I found the following Bug report which seems to be similar to my general deployment problem: https://jira.jboss.org/jira/browse/JBAS-6842 So I installed now JBoss AS 6.0.0 M1 and now the project with EJBs and JPA Entities deploys successfully without errors ! Also when the EJB modul only contains the ejb-jar.xml and the persistence.xml. All implementations classes are provided by jars placed in the /lib folder of my EAR. So it seems that the general EAR Folder layout is ok for JBoss AS 6.0. So for now I will go further with JBoss 6.0 - I found some new problems during deployment with my current Faclets and WebService configuration ;-) View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4269172#... Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&a...