The 1990 NBL season was the 12th season of competition since its establishment in 1979. With the addition of the Gold Coast Cougars a total of 14 teams contested the league.
The 1990 regular season took place over 23 rounds between 30 March 1990 and 22 September 1990.
|- bgcolor="#CCCCFF" font size=1 !width=90| Date !width=180| Home !width=60| Score !width=180| Away !width=260| Venue !width=70| Crowd !width=70| Box Score
|- bgcolor="#CCCCFF" font size=1 !width=90| Date !width=180| Home !width=60| Score !width=180| Away !width=260| Venue !width=70| Crowd !width=70| Box Score
|- bgcolor="#CCCCFF" font size=1 !width=90| Date !width=180| Home !width=60| Score !width=180| Away !width=260| Venue !width=70| Crowd !width=70| Box Score
|- bgcolor="#CCCCFF" font size=1 !width=90| Date !width=180| Home !width=60| Score !width=180| Away !width=260| Venue !width=70| Crowd !width=70| Box Score
|- bgcolor="#CCCCFF" font size=1 !width=90| Date !width=180| Home !width=60| Score !width=180| Away !width=260| Venue !width=70| Crowd !width=70| Box Score
|- bgcolor="#CCCCFF" font size=1 !width=90| Date !width=180| Home !width=60| Score !width=180| Away !width=260| Venue !width=70| Crowd !width=70| Box Score
|- bgcolor="#CCCCFF" font size=1 !width=90| Date !width=180| Home !width=60| Score !width=180| Away !width=260| Venue !width=70| Crowd !width=70| Box Score
|- bgcolor="#CCCCFF" font size=1 !width=90| Date !width=180| Home !width=60| Score !width=180| Away !width=260| Venue !width=70| Crowd !width=70| Box Score
|- bgcolor="#CCCCFF" font size=1 !width=90| Date !width=180| Home !width=60| Score !width=180| Away !width=260| Venue !width=70| Crowd !width=70| Box Score
|- bgcolor="#CCCCFF" font size=1 !width=90| Date !width=180| Home !width=60| Score !width=180| Away !width=260| Venue !width=70| Crowd !width=70| Box Score
|- bgcolor="#CCCCFF" font size=1 !width=90| Date !width=180| Home !width=60| Score !width=180| Away !width=260| Venue !width=70| Crowd !width=70| Box Score
|- bgcolor="#CCCCFF" font size=1 !width=90| Date !width=180| Home !width=60| Score !width=180| Away !width=260| Venue !width=70| Crowd !width=70| Box Score
|- bgcolor="#CCCCFF" font size=1 !width=90| Date !width=180| Home !width=60| Score !width=180| Away !width=260| Venue !width=70| Crowd !width=70| Box Score
|- bgcolor="#CCCCFF" font size=1 !width=90| Date !width=180| Home !width=60| Score !width=180| Away !width=260| Venue !width=70| Crowd !width=70| Box Score
|- bgcolor="#CCCCFF" font size=1 !width=90| Date !width=180| Home !width=60| Score !width=180| Away !width=260| Venue !width=70| Crowd !width=70| Box Score
|- bgcolor="#CCCCFF" font size=1 !width=90| Date !width=180| Home !width=60| Score !width=180| Away !width=260| Venue !width=70| Crowd !width=70| Box Score
|- bgcolor="#CCCCFF" font size=1 !width=90| Date !width=180| Home !width=60| Score !width=180| Away !width=260| Venue !width=70| Crowd !width=70| Box Score
|- bgcolor="#CCCCFF" font size=1 !width=90| Date !width=180| Home !width=60| Score !width=180| Away !width=260| Venue !width=70| Crowd !width=70| Box Score
|- bgcolor="#CCCCFF" font size=1 !width=90| Date !width=180| Home !width=60| Score !width=180| Away !width=260| Venue !width=70| Crowd !width=70| Box Score
|- bgcolor="#CCCCFF" font size=1 !width=90| Date !width=180| Home !width=60| Score !width=180| Away !width=260| Venue !width=70| Crowd !width=70| Box Score
|- bgcolor="#CCCCFF" font size=1 !width=90| Date !width=180| Home !width=60| Score !width=180| Away !width=260| Venue !width=70| Crowd !width=70| Box Score
|- bgcolor="#CCCCFF" font size=1 !width=90| Date !width=180| Home !width=60| Score !width=180| Away !width=260| Venue !width=70| Crowd !width=70| Box Score
|- bgcolor="#CCCCFF" font size=1 !width=90| Date !width=180| Home !width=60| Score !width=180| Away !width=260| Venue !width=70| Crowd !width=70| Box Score
The NBL tie-breaker system as outlined in the NBL Rules and Regulations states that in the case of an identical winâÂÂloss record, the results in games played between the teams will determine order of seeding.
<small><sup>1</sup>Head-to-Head between Eastside Spectres and Brisbane Bullets (1-1). Eastside Spectres won For and Against (+7). </small>
<small><sup>2</sup>Head-to-Head between Melbourne Tigers and Perth Wildcats (1-1). Melbourne Tigers won For and Against (+11).</small>
<small><sup>3</sup>Sydney Kings won Head-to-Head (2-0).</small>
There were two best of three Elimination finals, two best of three semifinals, and then best of three grand final series. All three of these finals were sudden death.
|- bgcolor="#CCCCFF" font size=1 !width=90| Date !width=180| Home !width=60| Score !width=180| Away !width=260| Venue !width=70| Crowd !width=70| Box Score
|- bgcolor="#CCCCFF" font size=1 !width=90| Date !width=180| Home !width=60| Score !width=180| Away !width=260| Venue !width=70| Crowd !width=70| Box Score
|- bgcolor="#CCCCFF" font size=1 !width=90| Date !width=180| Home !width=60| Score !width=180| Away !width=260| Venue !width=70| Crowd !width=70| Box Score