Harding was selected by the Detroit Pistons as the first player drafted into the National Basketball Association (NBA) without having played in college.

He spent parts of four seasons in the NBA with the Pistons and the Chicago Bulls during which he was the subject of team misconduct, criminal activity and a season-long league suspension.

[3] Thomas would maintain a connection with her son; she followed Harding during his high school career and developed a relationship with him during his adult life.

The legality of the selection was challenged immediately as the NBA rules stated a player could be drafted if they did not plan to enter college but needed to have been out of school for a full year.

Harding's prep school stint in Tennessee brought this into question and he was ultimately unable to sign with the team due to the technicality in his eligibility.

[11] In July 1962, National Basketball Association Board of Governors ruled that the Pistons could retain his player rights but he could not be signed until the 1963–64 NBA season.

[18] On January 18, 1964, the NBA authorized the Pistons to allow Harding, who had been touring with the exhibitional Harlem Road Kings, to join their roster.

[13] He averaged 11 points per game and played so well that Boston Celtics head coach Red Auerbach remarked about Harding before the 1964 NBA draft: "Say what they want to about all the fine, big fellows coming out of college in 1964, but the Pistons already have a guy who probably will outshine them all.

[24] Harding signed a one-year contract with the Pistons that totalled $15,000, where his return was heralded as being that of the "world's tallest reformed delinquent".

[24] Pistons player-coach Dave DeBusschere was elated to have Harding return and considered him "at least the fifth best center" in professional basketball when he last played – after Wilt Chamberlain, Bill Russell, Walt Bellamy and Nate Thurmond.

[29] Harding was fined by the Pacers on multiple occasions for misconduct and was ultimately suspended throughout the playoffs after he stopped attending practice.

[30] Pacers player Jerry Harkness believed that the team had a "good chance" to be ABA champions if Harding was not suspended.

[32][33] As a high school student, Harding allegedly raped Florence Ballard, a member of The Supremes, at knifepoint outside a Detroit ballroom in 1960.

[1][42] The character Raymond in the movie White Men Can't Jump, played by Marques Johnson, was based on Harding.