You need the c3p0-0.9.0.jar (Assuming hibernate 3.1.x) in your classpath View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4002290#4002290 Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&p=4002290