Hi Joern, the following works at least for our project | @Lob | @Basic(fetch=FetchType.EAGER) | @Column(name = "MESSAGE", nullable = true) | private byte[] message = null; | Our environment is JBoss AS 4.2.2.GA, JDK 1.5.x, Oracle 10g. Give it a try and hopefully your response will message success. BTW the given byte[] must be de-/serialized by some code written on your own. \sandor\ View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4162714#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...