During World War II the regiment mobilized 13 railway engineer battalions and three railroad operation battalions. The battalions saw service in Libya and Tunisia during the Western Desert Campaign and Tunisian Campaign, in Southern Ukraine as part of the Italian Expeditionary Corps in Russia, in Yugoslavia, Albania, Greece and France. In 1941 the 9th Company of the IV Railway Engineer Battalion built a combined road and rail bridge over the Corinth Canal, using an Austrian . The same battalion repaired the bridge over the Gorgopotamos river after the British-Greek Operation Harling had successfully destroyed the bridge on 25 November 1942. Another bridge repaired by the regiment's troops was the Stampetta Bridge in Slovenia. The regiment's I Railway Engineer Battalion served in Ukraine and Russia, where during the Battle of Arbuzovka the battalion fought in the frontline as infantry, earning a War Cross of Military Valour. After Italy changed sides with the Armistice of Cassibile on 8 September 1943 and the regiment and its battalions were disbanded by the Germans.