A 6'8" forward, Hankinson played at the University of Pennsylvania from 1970 to 1973. He participated on three Ivy League championship teams that reached the NCAA Tournament, and he was named team MVP in 1973.
After college, Hankinson was selected by the Boston Celtics in the second round of the NBA Draft. He appeared in two seasons with the Celtics before a knee injury ended his playing career. Hankinson held NBA career averages of 3.9 points per game and 1.8 rebounds per game. He also won an NBA championship ring with the Celtics in 1974.