I am currently performing that migration. During the migration process I have EJB2.1 and EJB3 in the same application. I don't plan to put this 2 ejb types together in production. However, it should work fine. Migrating only session bean is very simple and work quite fine. However, you will have to put these ejb3 in a separate jar file that your EJB2.1. When you will migrate you entities, the only problem I see in having both type of EJB is that I don't think you can have managed relationship between EJB2.1 entity and EJB3 entity. Otherwise migrating is going well. To accelerate a little bit the migration process, I have use xslt files created by oracle. You can find this xslt files at the following location: http://www.oracle.com/technology/pub/articles/vohra_ejb.html Hope this will help, An Phong Do www.solabs.com View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4205567#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...