The division began World War II in the district's 40th Rifle Corps alongside the 9th Rifle Division. It included the 75th, 177th, and the 248th Rifle Regiments, as well as the 32nd Light Artillery Regiment and the 104th Sapper Battalion. In July it became part of the newly formed 45th Army, covering the Turkish border. After the Red Army suffered heavy losses in the Battle of Kiev and in the Donbass, the 31st was one of the divisions sent north to fill the gap. By 12 October, it was at Taganrog on the coast of the Black Sea, assigned to the Taganrog Group, which became part of the 56th Army in November. With the army, the division fought in the Battle of Rostov and on the Mius during the winter of 1941–1942.