Frost remained in the army after the war, during which time he commanded the 1st Airborne Division's Battle School and returned from Norway with the division, still under Major-General Urquhart, back to the United Kingdom, where it was disbanded. He later returned to the 2nd Parachute Battalion, which still formed part of the 1st Parachute Brigade but was transferred to the 6th Airborne Division. Frost led his old battalion during the Palestine Emergency (see 6th Airborne Division in Palestine). While in Palestine he met his future wife, Jean McGregor Lyle, who was there as a welfare worker; they married on 31 December 1947 and had two children, a son and a daughter. Returning to England in late 1946, he attended the Staff College, Camberley, and, after graduating, became a General Staff Officer Grade 2 (GSO2) with the 52nd (Lowland) Infantry Division, a TA formation, before serving as a GSO1 with the 17th Gurkha Division during the Malayan Emergency. Returning to the United Kingdom, he was, from 1955 to 1957, in command of the Support Weapons Wing of the School of Infantry. He then commanded the 44th Parachute Brigade, another TA formation, composed of part-time soldiers, before receiving promotion to temporary major-general on 11 October 1961, and returning to the 52nd Division, this time as its GOC, a post he would hold for nearly three years.