On June 30, 1950, five days after the Korean War began; Thailand sent 4 tons of rice to South Korea. Thailand later provided additional support by contributing naval, air, and ground forces, as well as medical units.

The Thailand Army Division contributed a battalion-size unit of 1,000 soldiers. Advance elements of the Thai Infantry Battalion arrived in Korea on October 3, 1950 and the main body of soldiers arrived in November 1950. For their actions at Pork Chop Hill, soldiers from the 21st Thai Infantry Battalion were awarded one U.S. Legion of Merit, 12 Silver Stars, and 26 Bronze Star Medals. The Commander of the 8th U.S. Army gave them the nickname the "Little Tigers".
Thailand sent two naval frigates and one transport ship. The two Thai warships HTMS Prasae and HTMS Bangpakong arrived in South Korea on November 7, 1950 along with the transport ship, HTMS Sichang. The warships provided patrol and escort duties for United Nations Command and were replaced in December 1951, with two new frigates HTMS Tachin and HTMS Prasae II. Both departed South Korea on January 22, 1956.  The HTMS Sichang remained on the Peninsula until July 15, 1951. The Thai naval frigates served on the U.S. Naval Command Far East’s Blockade and Escort Force.

The Royal Thai Air Force supplied a C-47 transport aircraft for airlift operations and three task force contingents during and after the Korean War. The first Air Nursing Team arrived on December 26, 1950, and Air Liaison Officers and Airlift Mission Teams arrived on June 24, 1951. The C-47 departed South Korea on November 6, 1964. The Airlift Mission Teams and the Air Liaison Officers Teams departed in 1971, and the Air Nursing Teams departed in 1974. The air detachment remained in Korea until July 26, 1976.

Thai medical support included the Thai Air Force Medical Detachment, Red Cross Medical Service Detachment, and Mobile Surgical Hospital personnel.

Following the signing of the Armistice Agreement, the Thai infantry forces stayed in Korea until June 1972. During the course of the Korean War, Thailand dispatched a total of 11,786 soldiers, sailors, and air personnel to Korea.

Thailand suffered 1,273 casualties including 129 killed in action, 1,139 wounded in action, and 5 missing in action.

Thailand continues to contribute personnel in support of the UNC mission at the UNC Military Armistice Commission-Secretariat and within the UNC Honor Guard.