During the Battle of Madagascar in 1942, Brigadier Dimoline commanded the 22nd (East Africa) Infantry Brigade. His brigade carried out an amphibious landing on 10 September at Majunga, in the north-west part of the island. He commanded a surprise attack on 18 October against forces based at Andriamanalina with such success that his troops suffered no casualties. He was made a Commander of the Order of the British Empire (CBE) for his part in the battle.