In 1964, VMF(AW)-122 deployed to Naval Air Facility Atsugi for a year and returned to Marine Corps Air Station El Toro in January 1965. While at MCAS El Toro they transitioned to the F-4B Phantom and were redesignated VMFA-122. They deployed to the Republic of Vietnam in August 1967 and operated from Da Nang Air Base. For the next five months, the squadron flew 2540 sorties and delivered 4800 tons of ordnance. In February 1968, while supporting Marines during the Siege of Khe Sanh the squadron flew 629 sorties and dropped 1300 tons of ordnance. They rotated to Marine Corps Air Station Iwakuni in September 1968 and returned to Vietnam during the summer of 1969, this time operating from Chu Lai Air Base.