In 1966, Aziz passed out from the PMA Kakul with the class of 1st War Course, which is senior to 37th PMA but junior to 38th PMA Long Course, gaining commissioned as 2nd-Lt. in the 12th Battalion of the Punjab Regiment. He went to command an infantry platoon during the third war with India in 1971, and was later sent to attend the Command and Staff College where he qualified as a psc. He later went to attend the National Defence University where he graduated with MSc in War studies. In 1980s, Lt-Col. Aziz commanded the 12th Battalion before joining the Zia administration's staff.