I should have noticed this before. The System.out.println("IS AUTOCOMMIT: " + (conn.getAutoCommit())); prints false which means that AutoCommit has already been disabled. So its not the problem with autocommit. A little bit of reading the MySQL documents made me realize that unless your tables use "InnoDB" engine, transactions are not going to work. So i changed my table definition to use InnoDB engine instead of MyISAM engine (which is what i was using earlier). So your table definition should look like: anonymous wrote : CREATE TABLE `testtx` ( | `Name` varchar(255) default NULL | ) ENGINE=InnoDB DEFAULT CHARSET=latin1; | Changing the table definition and running the code worked perfectly with the insert getting rolled back when a RuntimeException is thrown. Give it a try. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4120890#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...