Naum Reznik was born in 1916 in Baku. His father Iefim, a native of Ukraine, fought in World War I on the Caucasus Front, and settled in Azerbaijan after the war. Naum's mother Rakhil was the daughter of an Ashkenazi rabbi from Baku. In 1917, the Reznik family moved to Tbilisi, Georgia. Upon finishing school, Naum worked as a technician at an airfield for agricultural aircraft. In 1935, he entered the Tbilisi State Forestry Institute, from which he graduated in 1940, whereupon he was drafted into the Red Army. He began his service in eastern Ukraine, with an engineering unit.
Following the outbreak of the Soviet-German War in June 1941, Naum Reznik, as the graduate of an institution of higher education, was sent to the Sumy artillery school (in northeastern Ukraine). However, in mid-August the Wehrmacht approached Sumy, and all the school cadets were formed into a battalion and sent to the frontline, in the area of Shostka. While defending that section, the unit came under German mortar fire, and it was decimated and dispersed. Reznik and his comrades found themselves surrounded. After making a long eastward trek, they managed to break through to the Soviet side. There, Reznik was promoted to the rank of lieutenant and attached to the 13th Guards Rifle Division, as the commander of a light artillery platoon. Shortly afterward, Reznik was wounded, and he underwent treatment at a medical-sanitary battalion (medsanbat). Somewhat later, he was seriously wounded and sent to a hospital in Voronezh, southern Russia. He would later recall [O.93/679] that the doctor who was about to clean his wound to prevent gangrene had no analgesics. Instead, he suggested that Naum embrace a young and lovely nurse with his healthy arm, in order to relieve the pain. According to Naum, it worked well.
After a long stay in hospitals, Naum Reznik was attached to the 32nd Separate Antitank Brigade, as the commander of a reconnaissance platoon. He saw action in the area of Voronezh. One day, he once again narrowly avoided being captured by the Germans, and was then forced to break out of enemy encirclement. After crossing the Don River, his regiment was reformed, and it took up defensive positions along the river: The Stalingrad operation was going on. Guards Captain Reznik, as the commander of an anti-tank company, held the defense against the Hungarian forces for two months. Then, the Soviet counter-offensive commenced, and Reznik's unit captured many Hungarian Jews – forced laborers who had been drafted by Horthy's pro-Nazi Hungarian regime to serve in the so-called labor battalions, and who were forced to dig trenches under Red Army fire.
In 1943, Guards Major Naum Reznik took part in the Kursk Salient operation and in the crossing of the Dnieper River. At the time, he served as the chief of staff of the 1852nd Anti-Tank Regiment. In the fall of 1944, he commanded the regiment for a short time, during the battles for the Dukla Pass between Slovakia and Poland. In January 1945, he took part in the liberation of Krakow in Poland, and ten days later he entered Auschwitz, which had been abandoned by the Nazis at the time. He was somewhat shocked to see that most of the Soviet soldiers felt no compassion toward the Jewish victims of the Nazis.
In the course of the war, Naum Reznik was awarded the Order of the Patriotic War, 2nd class; the Order of the Red Banner, and several medals. Immediately after the war, he was awarded the Order of the Patriotic War, 1st class.
Reznik was discharged from the army in 1946. In 1986, he immigrated to the USA, where his sons had settled earlier. He lived in Los Angeles.