Early life 
Militzok, who was Jewish, was born in The Bronx, New York. Recalling his childhood, he said: “I never saw a dirt field. Everything was cement. ... We had two choices: either go to the schoolyard and play ball or hang around on the corner and get in trouble. So, we played basketball all our lives.” He attended Stuyvesant High School, where he played for the basketball team.
He began his college basketball career as a freshman at CCNY in 1941, playing for a team that had a 16–1 record. He then transferred to Hofstra University, where he played for two seasons. World War II broke out, and he joined the Army. Stationed at Cornell University, he joined its basketball team in 1944.
Professional basketball career 
After the World War II, Militzok joined the New York Knicks in 1946 in the Basketball Association of America, which merged with the National Basketball League in 1949 to become the NBA. Militzok played in the first game in NBA history for the Knicks against the Huskies on November 1, 1946, and was credited with the first assist in the league's history. He was traded to the Toronto Huskies in February 1947.
In 1999, he and the other Jewish players on the Knicks, Sonny Hertzberg, Ralph Kaplowitz, Leo Gottlieb, Hank Rosenstein, and Ossie Schectman, were inducted into the National Jewish Sports Hall of Fame in New York.
After his basketball career, he became an attorney.
- "Militzok, Nat". Jews In Sports @ Virtual Museum. Retrieved August 11, 2011.
- "Nat Militzok NBA & ABA Statistics". Basketball-Reference.com. November 1, 1946. Retrieved August 11, 2011.
- "Deaths MILITZOK, NAT". New York Times. May 19, 2009. Retrieved August 11, 2011.
- "Basketball: The Original City Game". Jewishvirtuallibrary.org. Retrieved August 11, 2011.
- Bob Wechsler. Day by day in Jewish sports history. Retrieved August 11, 2011.
- "Nat Militzok". Miami Herald. May 19, 2009. Retrieved August 11, 2011.
- Robert Peterson. Cages to jump shots: pro basketball's early years. Retrieved August 11, 2011.
- Charles Rosen. The first tip-off: the incredible story of the birth of the NBA. Retrieved August 11, 2011.
- Jeffrey A. Kroessler. The Greater New York Sports Chronology. Retrieved August 11, 2011.
- George Kalinsky (1997). The New York Knicks: The Official 50th Anniversary Celebration. Macmillan USA. Retrieved August 11, 2011.