Ok, I think I have figured out what JBoss is doing. I am using 4.2.2GA. Here is the new use case I used: 1. Send JMS Message with JMSPriority 4 to Queue 2. Send JMS Message with JMSPriority 4 to Queue 3. Send JMS Message with JMSPriority 4 to Queue 4. Send JMS Message with JMSPriority 7 to Queue The MDB (Bean-Managed) is processing as follows: 1. Receives JMS Message #1, starts processing 2. Receives JMS Message #2, starts processing 3. Receives JMS Message #4, starts processing 4. Receives JMS Message #3, starts processing NOTE: All messages are queued before MDB finishes #1. What behavior is expected: 1. Receives JMS Message #1, starts processing 2. Receives JMS Message #4, starts processing 3. Receives JMS Message #2, starts processing 4. Receives JMS Message #3, starts processing It appears that JBoss is queuing up a message before the MDB even processes it. So a higher priority message must wait what appears to be the invoker-proxy-binding's # of messages before it jumps in front. This doesn't make sense to me, wouldn't you want a higher priority message to jump in front immediately? Is there a way around this, i.e. am I not setting the configuration correctly for my desired result? View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4110626#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...