Hi joern, try to add the @Lob annotation to the member. We hava had the same problem and changed to the newest oracle driver (somewhat ojdbc5.jar), but I can't remember exactly what leads us to the success (will investigate more when I'm back to office next monday). Another guess is to add a columndefinition to the @Column annotation like ... columndefinition="BLOB" ... . If all that won't work try to store the large object as chunks of byte[255] arrays, at least this will work. Hope this gives you any hints to solve the problem. Regards \sandor\ View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4162243#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...