The only way to effectively do this would be to set the <transaction-isolation></transaction-isolation> property in your *-ds.xml file. Unfortunately, this will be applicable to *all* connections used/created by EJB3 that use that datasource. EJB3 provides no way to acquire the underlying connection used by the EntityManager and as a result you will not be able to set this property dynamically. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3993701#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...