When you say you've checked the Hibernate Validators sources and think it should work properly, are you sure you are looking at the version you are actually using? In JBoss 4.2.1, I had to installer newer hibernate jars in order to get a working @Email validator as detailed here: http://www.jboss.com/index.html?module=bb&op=viewtopic&t=115318 Also, be aware that if you don't mark a field "required" on the input control, JSF will not submit a blank/empty text field for validation. Hibernate, however, will check for non-nullness, etc. when you do an update or persist, and this can cause an exception at persist time. So you need to be very careful to keep your validator annotations compatible with "required" (or non-required) input controls. I find this aspect of JSF (non)validation to be very error prone and wish it could be fixed, but it seems to be entrenched in the JSF lifecycle design, so we are forced to work around it. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4075911#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...