You didn't say much about how you exactly do it.
May be it is interesting for you, there is a bug in JIRA probably around your issue:
http://opensource2.atlassian.com/projec ... se/HHH-511.
and here there is a discussion about it:
http://forum.hibernate.org/viewtopic.ph ... collection
Anyway, delete-orphan will delete a child, if you explicitly remove it from the collection. Look at this exampe:
Code:
Parent parent = session.load(Parent.class, parentId);
parent.getChildren().remove(child1); // the child1 will be deleted
or
parent.getChildren().clear(); // all children of parent will be deleted