I ran another 5600 business transaction. My pergen size hovered around 48MB to 50MB (it would increase to 50MB and when I hit a full GC it was reduced to 48MB, at which point it would increase again unti lthe next full GC). Therefore, it would appear that there is an initial, substantial, increase in permgen usage when the EJBs are first used, after which the size increase is greatly reduced. I imagine that the amount of the increase depends on the number of different EJBs are deployed. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4172424#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...