The 1990 NBA playoffs was the postseason tournament of the National Basketball Association's 1989–90 season.

The tournament concluded with the Eastern Conference champion Detroit Pistons defeating the Western Conference champion Portland Trail Blazers 4 games to 1 in the NBA Finals.

This deciding game featured a missed dunk by Larry Bird late in the fourth with the Celtics trailing by four (103–99) and a clinching 3-point basket by Patrick Ewing on a play where he chased down an errant pass by Charles Oakley on the sideline in front of the Knicks' bench and hurled up a desperation shot as the shot clock was reaching zero.

The Phoenix Suns defeated the Los Angeles Lakers in a playoff series for the first time ever.

It also marked the first time since 1981 that the Lakers failed to reach the Western Conference Finals, ending the longest such run since the Bill Russell-led Boston Celtics, who made the Eastern Conference Finals thirteen consecutive times between 1957 and 1969.

The Chicago Bulls lost Game 7 of the Eastern Conference Finals 93–76 in Detroit, making it the third straight year they were ousted in the playoffs by the Pistons.