ok I realized what we were doing wrong... Instead of creating a consumer from an IQueue I was creating it from an IDestination, which was not seeing the query params I was setting.
This page helped: http://activemq.apache.org/nms/activemq-destination-options.html So rather than doing: IMessageConsumer _consumer = _session.CreateConsumer (_destination); I switched it to IMessageConsumer _consumer = _session.CreateConsumer(queueWithParams); using a string made of queueName?params -- View this message in context: http://activemq.2283324.n4.nabble.com/prefetch-size-variations-with-nms-connections-tp4668250p4668332.html Sent from the ActiveMQ - User mailing list archive at Nabble.com.