In the wake of reports that he might rejoin the team for their home game against the Los Angeles Lakers Wednesday night, Tomjanovich held a morning news conference to announce that he will be gone indefinitely.
"After having a week or so to process all the things that have happened, in talking to the doctors and (team owner Les Alexander), we're all in agreement that the best thing for me personally is to take a leave of absence," Tomjanovich said.
Larry Smith will remain the interim coach in his absence.
On March 18, Tomjanovich was diagnosed with a superficial bladder tumor that did not require surgery, but does mandate once-a-week treatments. He has remained at his Houston home for much of the last week, and missed the team's five-game road trip that concluded Monday.
Tomjanovich, who never had missed a regular-season game as Rockets' coach before the diagnosis, is in his 12th season as Rockets coach.
The Rockets begin play Wednesday in the eighth and final playoff spot in the Western Conference, one game ahead of the Phoenix Suns.