 <p>There are <a href="http://groups.google.com/group/nhusers/browse_thread/thread/1e5c71502dd547f0/a7908ea36bed6a5e" rel="nofollow noreferrer">some</a> evidences that NHibernate <a href="https://forum.hibernate.org/viewtopic.php?p=2398761" rel="nofollow noreferrer">does not support</a> stored procedures using <code>sys_refcursor</code>.</p> <hr> <p>UPDATE: It seems that this has been <a href="http://216.121.112.228/browse/NH-847?page=com.atlassian.jira.plugin.system.issuetabpanels:changehistory-tabpanel" rel="nofollow noreferrer">fixed in 2.1.1.GA</a></p>