in case you want relative path try this.. <jar-file>file:my-application.war!/WEB-INF/lib/myapp1.jar</jar-file> otherwise the best/cleaner option is to bundle your application as ear, with the entity jars directly inside the ear myapp.ear ---entity.jar ---mywebapp.war ------WEB-INF ---------lib on that case you will just need to specify as <jar-file>entity.jar<jar-file> in the persistence.xml or just bundle your persistence.xml inside the entity.jar/META-INF post this question in hibernate forum, you could get better answers. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4122836#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...