More of a EJB3 question, but I think you need to change: | @OneToMany(mappedBy="workout", cascade=CascadeType.REMOVE) | private List<Workout> workouts = new ArrayList<Workout>(); | to | @OneToMany(mappedBy="athlete", cascade=CascadeType.REMOVE) | private List<Workout> workouts = new ArrayList<Workout>(); | You need to specify the field in the Workout entity which maps back to this object. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4072211#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...