Transferred to the Eastern Front in July, the division joined XXXV Army Corps, under the direct control of Army Group Centre, to reduce the encircled Soviet troops around Minsk and participated in the Siege of Mogilev. The 15th went on to fight in the Battle of Smolensk during August as part of the XXXXVI Army Corps of the 2nd Panzer Group. It became part of the IX Army Corps of the 4th Army, facing the Soviet Yelnya Offensive in September. The division participated in the encirclement of Soviet forces around Vyazma when Operation Typhoon began the Battle of Moscow in October as part of the XX Army Corps of the army. The division was transferred to the XII Army Corps in November and December before returning to XX Corps in January 1942 for battles near Yukhnov. After fighting in the Gzhatsk sector from February as part of the XX, VII, and V Army Corps of the 4th Panzer Army, the division was withdrawn to France to rebuild in May after temporarily disbanded five battalions due to losses. In a propaganda move, the infantry regiments of the division were renamed grenadier regiments along with all German infantry regiments on 15 October 1942.