In December 1942 Rudnicki was promoted to Colonel, and in April was named commandant of the 6th Infantry Division. He fought in the Battle of Monte Cassino and Battle of Bologna. On 1 April 1945 Rudnicki was promoted to Generał brygady, and in May, after the war had ended, he was named commandant of the 1st Armoured Division, and until 1947, remained in northwestern Germany.