Hi BGMF, 1. Download a JDBC driver from the MySQL site. http://dev.mysql.com/downloads/connector/j/5.0.html and put it into the lib or deploy directory of your server configuration. 2. Copy <JBoss_Home>\docs\examples\jca\mysql-ds.xml to your deploy directory and adjust it. Basically you simply have to adjust the connection url, driver-class, user-name and password. If user-name or password are wrong you might get a funny exception about the wrong Hibernate dialect which can be confusing. 3. The jndi-name of your datasource must be referenced in your persistence.xml file like java:/ Basically all the code to make this work (except for the problem I have) is listed in my example. Hope that helps, otherwise what exactly is your problem? Greetings, Hans View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4089967#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...