Reactivated in 1957, the battalion deployed to Vietnam in 1965 and fought the division's first engagement from 18 to 20 September as part of Operation Gibraltar. On 2 February 1968 during the Battle of Huế the battalion was deployed from Camp Evans to PK-17 to launch an attack towards La Chu to close off the PAVN supply routes west of Huế. The 2/12th Cavalry was pinned down by superior PAVN forces and eventually broke out on the night of 3 February leaving their dead behind. The battalion participated in the Cambodian Incursion and earned its 16th campaign streamer for the Sanctuary Counteroffensive. Serving as battalion signal officer during the Battle of Khe Sanh was future U.S. Senator Max Cleland.