The M48s saw extensive action during the Vietnam War. Over 600 Pattons would be deployed with US Forces during the war. The initial M48s landed with the US Marine 1st and 3rd Tank Battalions in 1965; the Marine 5th Tank Battalion would later become a reinforcement unit. Remaining Pattons deployed to South Vietnam were in three U.S. Army battalions, the 1-77th Armor near the DMZ (67 M48A2C (23 tanks supplied from US Army Training Center at Fort Knox, Ky USA and 44 tanks from Letterkenney Army Depot Chambersburg PA USA) tanks were used by the 77th Armor from August 1968 to January 1969. These were replaced with M48A3s), the 1-69th Armor in the Central Highlands, and the 2-34th Armor near the Mekong Delta. Each battalion consisted of approximately fifty seven tanks. M48s were also used by Armored Cavalry Squadrons in Vietnam, until replaced by M551 Sheridan Armored Reconnaissance Airborne Assault Vehicles (ARAAV) in the Divisional Cavalry Squadrons. M48A3 tanks remained in service with the 11th Armored Cavalry Regiment until the unit was withdrawn. The M67A1 flamethrower tank (nicknamed the Zippo) was an M48 variant used in Vietnam.
The M48 Patton has the distinction of playing a unique role in an event that was destined to radically alter the conduct of armored warfare. When US forces commenced redeployment operations, many of the M48A3 Pattons were turned over to the Army of the Republic of Vietnam (ARVN) forces, in particular creating the ARVN 20th Tank Regiment; which supplemented their M41 Walker Bulldog units. During the North Vietnamese Army (NVA) Easter Offensive in 1972, tank clashes between NVA T-54/PT-76 and ARVN M48/M41 units became commonplace. But on 23 April 1972, tankers of the 20th Tank Regiment were attacked by an NVA infantry-tank team, which was equipped with the new 9M14M Malyutka (NATO designation: Sagger) wire guided anti-tank missile. During this battle, one M48A3 Patton tank and one M113 Armored Cavalry Assault Vehicle (ACAV) were destroyed, becoming the first losses to the Sagger missile; losses that would echo on an even larger scale a year later during the Yom Kippur War in the Middle East in 1973.
The M48s performed admirably in Vietnam in the infantry-support role. However, there were few actual tank versus tank battles. One was between the US 1-69th Armor and PT-76 light amphibious tanks of the NVA 202nd Armored Regiment at Ben Het Camp in March 1969. The M48s provided adequate protection for its crew from small arms, mines, and rocket-propelled grenades. South Vietnamese M48s and M41s fought in the so-called Ho Chi Minh Offensive in 1975. In several incidents, the South Vietnamese Army successfully defeated NVA T-34 and T-55 tanks and even slowed the North's offensive. However since the United States Congress passed bans on the transfer of fuel and ammunition to South Vietnam, the American-made tanks were soon out of ammunition and fuel and were abandoned to the North Vietnamese Army in 1975 which put them in predictably short service of the Vietnamese People's Army after the war ended in May 1975.
M48s, alongside Australian 20 pounder (84mm) gunned Centurions of the 1st Armoured Regiment, were the only vehicles in Vietnam that could reasonably protect their crews from land mines. They were often used for minesweeping operations along Highway 19 in the Central Highlands, a two lane paved road between An Khe and Pleiku. Daily convoys moved both ways along Highway 19. These convoys were held up each morning while the road was swept for mines. At that time, minesweeping was done by soldiers walking slowly over the dirt shoulders of the highway with hand-held mine detectors. During this slow process, convoys would build up into a dangerously inviting target for the enemy. As a result a faster method was improvised, the "Thunder Run", in which one M48 lined up on each side of the road, with one track on the dirt shoulder and the other track on the asphalt; then with all guns firing, they raced to a designated position miles away. If the M48s made it without striking a mine, the road was clear and the convoys could proceed. In most cases, an M48 that struck a land mine in these operations only lost a road wheel or two in the explosion; seldom was there any hull damage which would be considered "totaling" the tank.
M47s and M48s were again used in tank warfare by the Pakistan Army against Indian Army Centurion and M4 Sherman tanks in the Indo-Pakistani War of 1965 with some good results. In the Rann of Kutch the tanks proved surprisingly nimble in marshy terrain, and Pakistani forces drove back Indian attacks. In Kashmir and Punjab, the tank had its first real test. During Operation Grand Slam, Pakistani tank forces broke through the Indian lines very quickly, and defeated armored counterattacks. The Pakistanis used approximately a division worth of tanks though not all were Pattons. The Patton failed to live up to expectations in the Battle of Asal Uttar, where about 97 Pakistani tanks were lost, the majority of them being Pattons. Later the tank was the main Pakistani tank at the Battle of Chawinda and its performance at that battle was deemed satisfactory.The Patton was later used by Pakistan in the Indo-Pakistani War of 1971, with mixed results. In a repetition of 1965, Pattons spearheaded the Pakistani advance through Chamb, and the Patton was the main Pakistani tank at Shakarghar. In the latter battle, a brigade of tanks (the Changez Force) successfully resisted the Indian advance, in a repeat of Chawinda. However, in what became known as Pakistan's Charge of the Light Brigade, a counterattack led by 13th Lancers and 31st Cavalry was mauled by the Indian 54th Division around Battle of Barapind. India later set up a war memorial named "Patton Nagar" ("Patton City") in Khemkaran District, where the captured Pakistani Patton tanks are displayed.
Analyzing their performance, the Pakistani Army held that the Patton was held in reasonably high esteem by both sides and that tactics were to blame for the debacle at Asal Uttar. However, a U.S. study of the battles in South Asia concluded that the Patton's armor could in fact be penetrated by the 20 pounder gun (84 mm) of the Centurion as well as the 75 mm gun of the AMX-13.
M48s were also used with mixed results during the 1967 Six-Day War. On the Sinai front, Israeli M48s up-gunned with 105 mm L7 rifled guns were used with success against Egyptian IS-3s, T-54s, T-54s, T-34s and SU-100s supplied by the Soviet Union in the second battle of Abu-Ageila. However, on the West Bank front, Jordanian M48s were often defeated by Israeli 105mm Centurions and WWII-era M4 Shermans (M-51s up-gunned with 105 mm guns). In pure technical terms, the Pattons were far superior to the Shermans, with shots at more than 1,000 meters simply glancing off the M48s' armor. However, the 105 mm gun of the Israeli Shermans fired a HEAT round designed to defeat the T-62 tank, which was the Soviet response to the M48's successor in US service, the M60. The Jordanian Pattons' failure on the West Bank could also be attributed to Israeli air superiority. The Israeli Army captured about 100 Jordanian M48 and M48A1 tanks and pressed them into service in their own units after the war.
M48s were used by the Israel Defense Forces, the Lebanese Army, the Christian Lebanese Forces militia, the Druze Progressive Socialist Party militia and the South Lebanon Army in the Lebanese Civil War. On 10 June 1982, ten Israeli M48A3s and some APCs were lost in an ambush by Syrian T-55 tanks and BMP-1 during the Battle of Sultan Yacoub.
The Lebanese Army still operates about 100 M48s. In 2007, during the 2007 North Lebanon conflict Lebanese Army M48s shelled militant outposts in a refugee camp.
Together with the M47, M48 tanks were used by the Turkish Armed Forces during the Turkish invasion of Cyprus in 1974. The Turkish Armed Forces in Northern Cyprus continue to use M48 tanks today.
Iranian M48 tanks were used widely in the Iran-Iraq War.
In 1987, United States sold Morocco 100 M-48A5 tanks from the Wisconsin National Guard. They were used in Western Sahara desert against Polisario guerrillas.
Pakistan used M48 Pattons while reinforcing American troops during the Battle of Mogadishu in 1993.