Patrick Montgomery was called to the Bar at Lincoln's Inn in London in 1973 and admitted to practice in 1974 in Victoria. He practised as a solicitor until February 2003 when he resigned as a partner of Deacons to join the Bar.
As a solicitor, Patrick practised extensively in commercial litigation, insurance and personal injury law. He was an accredited specialist with the Law Institute of Victoria in personal injury law. From 1996 to 2002 Patrick was chairman of the litigation lawyers section of the Law Institute.
Patrick has conducted litigation in all Victorian jurisdictions and was a Law Institute representative on the LIV/AMA (Vic) Medico Legal Committee and LIV/County Court Liaison Committee.