Patrick enlisted into the Citizens Military Force (Reserve) on 29 Apr 1942 and joined 102nd Anti Tank Regiment, Royal Australian Artillery (RAA) on 1 May 1942. He transferred to the 104th Anti Tank Regiment, RAA on 6 Jul 1942 and joined the AIF on 20 Jul 1942. He transferred to 1st Australian Infantry Training Battalion on 19 Jul 1944, then 32nd Australian Infantry Training Battalion on 8 Aug 1944. he was selected and transferred to 1st Australian Commando Training Squadron on 20 Nov 1944.
Patrick joined the unit on 31 Jan 1945 and embarked for New Britain aboard “TAROONA” on 9 Apr 1945 with the unit as a Trooper in No 9 Sect, “C” Troop. He left the unit on 26 Dec 1945 and returned to Australia on 16 Jun 1946.
He was discharged on 20 Jun 1946.
He was entitled to the 1939-45 Star, Pacific Star, War Medal and Australian Service Medal 1939-45, pictured below. He is now also entitled to the Australian Service Medal 1945-75 with a clasp "S.W.Pacific".