The Charlotte Hornets were aligned in the Midwest Division in the Western Conference. Charlotte would be aligned in the Central Division for good starting the next year. The league had placed the four new teams in different divisions to spread them out over their first few seasons.
After seventeen seasons as the broadcast television home for NBA basketball, CBS Sports aired its final NBA broadcast in Game 5 of the Finals from Portland. NBC Sports would begin a twelve-season run as the league's new broadcast partner beginning the next season.
This was also the first season that Turner Sports aired games on its, at the time, new cable outlet Turner Network Television; this began a long relationship between TNT and the NBA that would run until the end of the 2024–25 season.
The NBA adopted the FIBA rule that game clocks register tenths of seconds in the final minute of a quarter. This rule turns controversial during the season because of clock calibration problems in many venues; following a January 15, 1990, game at Madison Square Garden between the New York Knicks and the Chicago Bulls where Trent Tucker sank a three-point basket with the ball put in play with one-tenth of a second remaining, the NBA mandated clock calibration and prohibited any shot made when the ball is put in play with less than three-tenths of a second remaining from counting unless it is a dunk or a tip-in. The Trent Tucker Rule would be established the following year as a result of this incident.
All three Texas-based teams made the playoffs. This would not happen again until 2004.
This was the last of nine consecutive seasons in which the Lakers finished as the No. 1 seed in the Western Conference. They would not return there until 2000.
On March 28, 1990, near the end of the 1989–90 season, the Cleveland Cavaliers faced their new nemesis Michael Jordan. Needing the victory to clinch a playoff berth, Jordan set his career high with 69 points in an overtime win and putting a dent in the Cavaliers' playoff plans.
The Spurs orchestrated the biggest turnaround, with rookie David Robinson at center. After finishing 21–61 in 1988–89, they improved by 35 games and won the Midwest Division.
Scottie Pippen becomes the first forward in NBA history to accumulate over 200 steals with over 100 blocks in a season.
Teams in bold advanced to the next round. The numbers to the left of each team indicate the team's seeding in its conference, and the numbers to the right indicate the number of games the team won in that round. The division champions are marked by an asterisk. Home court advantage does not necessarily belong to the higher-seeded team, but instead the team with the better regular season record; teams enjoying the home advantage are shown in italics.