"July Pyrra" wrote : could it come from the fact that it's injected in a class called by the main class (web service) and therefore not deployed or something like that? As long as you are "looking-up" an EJB (in this case the Query EJB), and not creating an instance yourself, the injection should work. That's the reason i was interested in the code which uses this EJB. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4153382#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...