Your call to methodB() is an ordinary call of a method, not intercepted by the EJB container; at run-time the EJB container will inject a proxy and not an instance of your class, this is the way it intercepts calls and setup the environment before calling your method. If you use this you’re calling a method directly and not through the proxy. Hence both methods will use the same transaction, regardless to what is defined in ejb-jar.xml for calls through EJB interfaces.