I found a possible explanation to this problem. It seem's the discriminant is'n't used when requesting by a one-to-many in an subclass. So a way to make hibernate consider the hierarchy is to force control on the Discriminator column. With annotations, @Where should be used. @Where(clause="POI_TYPE='B'") and @Where(clause="POI_TYPE='C'") But in my example, I really don't understand where I have to place this clauses. Any help ? Thanks Paulin View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4110262#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...