Pitkin County recommissioned at Long Beach Naval Shipyard on 9 July 1966 with Lieutenant C. E. Quarles in command.
The same day she became flagship for Landing Ship Squadron 3.
After training through the summer, she sailed for South Vietnam and arrived Da Nang on 29 November.
After debarking Marines, she began shuttle operations between Da Nang and Chu Lai until sailing for Guam on 21 December, arriving at Apra Harbor on 2 January 1967.
On 26 January she got underway for a survey cruise taking her to the Marianas, Volcano Islands, Bonins, and Ryukyus.
Arriving at Okinawa on 7 February, she loaded supplies and vehicles and sailed on the 10th for Chu Lai, arriving on the 14th.
After unloading, she sailed via Da Nang for Hong Kong.

For the next three years, operating out of Guam, she alternated service in Vietnam, largely for Operation Market Time operations with visits to other Far Eastern ports.
On Christmas Eve she sped to assist the merchant tug Makah ablaze in Vũng Tàu Harbor, and extinguished the fires saving the stricken and abandoned ship.
Pitkin County recommissioned at Long Beach Naval Shipyard on 9 July 1966 with Lieutenant C. E. Quarles in command. The same day she became flagship for Landing Ship Squadron 3. After training through the summer, she sailed for South Vietnam and arrived Da Nang on 29 November. After debarking Marines, she began shuttle operations between Da Nang and Chu Lai until sailing for Guam on 21 December, arriving at Apra Harbor on 2 January 1967. On 26 January she got underway for a survey cruise taking her to the Marianas, Volcano Islands, Bonins, and Ryukyus. Arriving at Okinawa on 7 February, she loaded supplies and vehicles and sailed on the 10th for Chu Lai, arriving on the 14th. After unloading, she sailed via Da Nang for Hong Kong.
For the next three years, operating out of Guam, she alternated service in Vietnam, largely for Operation Market Time operations with visits to other Far Eastern ports. On Christmas Eve she sped to assist the merchant tug Makah ablaze in Vũng Tàu Harbor, and extinguished the fires saving the stricken and abandoned ship.
USS Pitkin County (LST-1082)