Isaak Chizhik was born in 1907 in Vasilkov, 25 kilometers south of Kiev. His father, a tinsmith, and his mother, were killed in February 1919 during a pogrom perpetrated by Petliura's Ukrainian army. Needing to provide himself with food, the young orphan began as the helper of a blind person. It is not known how he subsisted after that, but when the civil war in Ukraine ended, he was an inmate of a penal colony for young people. After his release from the colony, Chizhik worked at a factory in Kiev. In 1929, he was drafted into the Red Army. In the 1930s, he graduated from an artillery school and then from the M.V. Frunze Military Academy in Moscow. After that, he continued his military service with the rank of captain.
When the Soviet-German war began in June 1941, Chizhik was a teacher at the First Omsk Artillery school (Western Siberia), with the rank of major. He requested to be sent to the front lines, but this request was rejected since the command of the school wanted to retain its best teacher. In December 1941, he repeated his request and the result was the same. Only his third request, submitted in January 1942 to the head of artillery of the West-Siberian Military District, was fulfilled, and Chizhik went to the Kalinin [Western] Front as the head of artillery of an infantry brigade. With this brigade, he took part in fighting at the Valdai Hills, in the Spas-Demensk operation in 1943, in the recapture of Latvia in 1944, and in many other operations of the Red Army. He was awarded three military orders. Despite his position as a HQ officer, Chizhik often appeared on the front lines, personally supervising the artillery fire. Eyewitnesses recalled that he never cowered before enemy fire, always standing straight and tall, even laughing at those soldiers who were clearly afraid of enemy shells.
A correspondent of the Yiddish newspaper Eynikayt asked Chizhik if he had suffered minutes of mortal fear. Chizhik replied: "Believe me: I don't want to die. I have three sons. But I don't want people to say that Jews are cowards."
After the war, Chizhik continued in military service. He retired in 1983 and settled in Leningrad.