Walk was drafted in the first round (second pick overall) of the 1969 NBA Draft by the Phoenix Suns, after they lost a coin toss with the Milwaukee Bucks for the number one pick, which turned out to be Lew Alcindor (later known as Kareem Abdul-Jabbar).
He played for the Suns from 1969 to 1974, was traded to the then New Orleans Jazz, and subsequently traded to the New York Knicks, where he played for two seasons. Afterward, he went to play in Venice, Italy, then in Israel with Hapoel Ramat Gan.
In 1988 it was discovered that Walk had a benign tumor enveloping his spine. Following surgery Walk was left in a wheelchair, from which he played wheelchair basketball for the L.A.-Phoenix Samaritans in the Southern California league of the National Wheelchair Basketball Association.
In 1990 Walk was honored at the White House by U.S. President George H. W. Bush, as the "Wheelchair Athlete of The Year." He later worked for the Phoenix Suns in the Community Affairs department.
Walk is in the Miami Beach Senior High School Hall of Fame, a "Gator Great" in the University of Florida Athletic Hall of Fame, and the Jewish Sports Hall of Fame.