I solved my problem ! In fact my Seam component with action methods was both a "JBPM listener" and "JSF listener". It had methods with @StartTask end @EndTask annotations, that were called from a JSF page. I finally thought that it was not a good architecture choice, so I splitted my Seam component in a JSF listener component (with @StartTask and @EndTask annotated methods) and a JBPM listener component. And the injection of business process instance and variables into this JBPM listener worked ! So what I see is that you can't have @StartTask and @EndTask methods in a JBPM listener. Is it something expected or is it a bug ? And if this is not a bug, could anyone explain to me the reason of all this ? Thanks in advance View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4089674#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...