It looks like the EJB3 spec does not support an entity bean with a FK as part of its compound PK. I've managed to find JBoss/hibernate docs which describe their work around for the problem, and I've managed to get that to work. The last hurdle that I can't figure out is how to map the reverse association. It looks like the ManyToOne in the Embedded PK isn't actually part of the EntityBean and so I can't reference it in the mapped by clause from the associated Entity Bean. Abbreviated table structure is as follows: tblParent parentId (PK) ... tblChild parentId (FK) (PK) sequence (PK) ... Very Abbreviated Entities as follows: @Entity public class ParentBean { ... /** HOW SHOULD I ANNOTATE THIS **/ @OneToMany(mappedBy="parent") <-- DOESNT WORK @OneToMany(mappedBy="pk.parent") <-- DOESNT WORK public Set< ChildBean > getChildren(); public void setChildren(Set< ChildBean > children); ... } @Entity @AssociationOverride( name="pk.parent", joinColumns = @JoinColumn(name="parent_parentId") ) public class ChildBean { @EmbeddedId public ChildPK pk; } @Embeddable public class ChildPK { @ManyToOne public ParentBean parent; public Integer sequence; } View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3972208#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...