The first assignment of the B-32 began when General George Kenney, the commander of Allied air forces in the South West Pacific Area and commander of the U.S. Fifth Air Force, traveled to Washington D.C. to request B-29s. Since priority had been given to strategic bombing by the B-29, Kenney’s request was denied, after which he requested the B-32.
Following a demonstration, the Army General Staff agreed that Kenney could conduct a combat evaluation, and a test schedule of 11 missions was set up, followed by a plan to convert two of the 312th Bomb Group's four Douglas A-20 Havoc squadrons to B-32s. Project crews took three B-32s to Clark Field, Luzon, Philippine Islands, in mid-May 1945 for a series of test flights completed on 17 June.
The three test B-32s were assigned to the 312th BG's 386th Bomb Squadron. On 29 May 1945, the first of four combat missions by the B-32 was flown against a supply depot at Antatet in the Philippines, followed by two B-32s dropping 16 2,000 lb (910 kg) bombs on a sugar mill at Taito, Formosa, on 15 June. On 22 June, a B-32 bombed an alcohol plant at Heito, Formosa, with 500 lb (230 kg) bombs, but a second B-32 missed flak positions with its 260 lb (120 kg) fragmentation bombs. The last mission was flown on 25 June against bridges near Kiirun on Formosa.
The test crews were impressed with its unique reversible-pitch inboard propellers and the Davis wing which gave it excellent landing performance. However, they found a number of faults: the cockpit had an extremely high noise level and a poor instrument layout, the bombardier's vision was impaired, it was overweight and the nacelle design resulted in frequent engine fires (Note: the latter deficiency was also shared with the Dominator's counterpart, the B-29 Superfortress), yet the testing missions were mostly successful.
In July 1945, the 386th Bomb Squadron completed its transition to the B-32, flying six more combat missions before the war ended. On 13 August, the 386th BS moved from Luzon to Yontan Airfield on Okinawa and flew mostly photographic reconnaissance missions. The missions were intended to monitor Japan's compliance with the ceasefire and to gather information such as possible routes occupation forces could take into Tokyo. During the two-hour engagement, the Dominators suffered only minor damage and none of their crew were injured. "Though the B-32 gunners later claimed to have damaged one fighter and 'probably destroyed' two others, surviving Japanese records list no losses for that day or next." Based on the Japanese action on the 17 August, U.S. commanders felt that it was important to continue the reconnaissance missions over Tokyo so they could determine if it was an isolated incident or an indication that Japan would reject the ceasefire and continue fighting.
On 18 August 1945, four Dominators were given the task of photographing many of the targets covered on the previous day; however, mechanical problems caused two to be pulled from the flight. Over Japan, a formation of 14 A6M Zeros and three N1K2-J Shiden-Kai fighters (George) but apparently mis-identified as Ki-44 Tojos, by the American crews) attacked the remaining two U.S. aircraft. Saburo Sakai, a Japanese ace, said later that there was concern that the Dominators were attacking. Another Japanese ace, Sadamu Komachi, stated in a 1978 Japanese magazine article that the fighter pilots could not bear to see American bombers flying serenely over a devastated Tokyo.
The B-32 Dominator Hobo Queen II (s/n 42-108532) was flying at 20,000 ft (6,100 m) when the Japanese fighters took off and received no significant damage. Hobo Queen II claimed two Zeros destroyed in the action as well as a probable Shiden-Kai. Japanese records show that no aircraft were lost. The other Dominator was flying 10,000 ft (3,000 m) below Hobo Queen II when the fighters took off. The fighters heavily damaged that Dominator, initially wounding the dorsal gunner and then seriously wounding two other members. Photographer Staff Sergeant Joseph Lacharite was wounded in the legs (his recovery required several years). Sergeant Anthony Marchione, a photographer's assistant, helped Lacharite and then was fatally wounded himself. Marchione was the last American to die in air combat in World War II. Despite the damage, the Dominator returned to Okinawa, however, the incident precipitated the removal of propellers from all Japanese fighters as per the terms of the ceasefire agreement, beginning 19 August 1945. The last B-32 combat photo reconnaissance mission was completed on 28 August, during which two B-32s were destroyed in separate accidents, with 15 of the 26 crewmen killed. On 30 August, the 386th Bomb Squadron stood down from operations.
Production contracts of the B-32 were cancelled on 8 September 1945, with production ceased by 12 October. Many B-32s ended up being salvaged at Walnut Ridge, Arkansas with a total of 38 flown to Kingman Army Airfield for disposal. The large club pip of the 386th is visible on one B-32 awaiting reclamation. Five of Kingman's Dominators were from the 386th Bomb Squadron, 312th Bomb Group's overseas assignment. Along with several other noteworthy aircraft on temporary display at Davis Monthan AFB after World War II, the last surviving Dominator, B-32-1-CF #42-108474 was written off and destroyed in 1949.