Iosif Slutskii was born in 1912. During the war he served as an adjutant of a rifle battalion. He was called up to the Red Army in October 1941 and within a year was on the front lines. He took part in the battle of Stalingrad, for which, in December 1942, he was awarded the For the Defense of Stalingrad Medal. In September 1943 he received the For Bravery Medal for his role in the crossing of the Northern Donets River.
In October 1943 he took an active part in breaking through the German defenses in the area of the city of Zaporozhe. Under heavy enemy fire but without any losses the battalion under Slutskii's command succeeded in getting past two mined anti-tank trenches. For this and other achievements on December 9, 1943 Slutskii was awarded the Order of the Red Star.
In August 1944, then a captain, Slutsky was awarded the Order of the Patriotic War, 2nd class, for successfully carrying out several military operations between February and May 1944.
Slutskii was killed on February 13, 1945 during the battle to liberate the Polish city of Poznań. He was buried on the Alley of Heroes at the military cemetery there.