In 2005 Jackman signed for Leinster. A broken leg hindered his early Leinster career but he eventually established himself as a first team regular. He was a prominent member of the team that won the 2007–08 Celtic League title and he also earned himself a recall into the senior Ireland squad. He has now retired from the professional game after a concussion injury in 2010. Bernard Jackman has become an acting ambassador for Acquired Brain Injury Ireland, standing strongly behind the concussion awareness campaign 'Mind your Head in Sport'. John Fogarty another Leinster Hooker had to retire with a similar concussion injury soon after.