Mize subsequently participated in the landing on Inchon at the beginning of September 1950 and later took part in the fighting near Hill 216 in the vicinity of Seoul, where commander of Company G, Robert D. Bohn was wounded on September 23 and evacuated to the rear for treatment. Mize subsequently assumed command of the Company G and led it during the recapture of Seoul, where he participated in the heavy street combats. He was wounded, but refused to be evacuated and continued to lead his company during the capture of General Government Palace, where Marines under his command tore down North Korean flags flying over its dome and ran up American flags, then routed the enemy troops, moving room by room. For this act of valor, Mize received the Navy Cross, the United States military's second-highest decoration awarded for valor in combat. He also received Gold Star in lieu of his second Purple Heart for wounds.