The 1998–99 NBL season was the 21st season of competition since its establishment in 1979. A total of 11 teams contested the league. This season marked the first summer season for the NBL. The Townsville Suns were renamed the Townsville Crocodiles.
Regular season The 1998–99 regular season took place over 23 rounds between 9 October 1998 and 14 March 1999.
Round 1
|- 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| Boxscore
Round 2
|- 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| Boxscore
Round 3
|- 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| Boxscore
Round 4
|- 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| Boxscore
Round 5
|- 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| Boxscore
Round 6
|- 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| Boxscore
Round 7
|- 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| Boxscore
Round 8
|- 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| Boxscore
Round 9
|- 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| Boxscore
Round 10
|- 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| Boxscore
Round 11
|- 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| Boxscore
Round 12
|- 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| Boxscore
Round 13
|- 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| Boxscore
Round 14
|- 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| Boxscore
Round 15
|- 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| Boxscore
Round 16
|- 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| Boxscore
Round 17
|- 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| Boxscore
Round 18
|- 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| Boxscore
Round 19
|- 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| Boxscore
Round 20
|- 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| Boxscore
Round 21
|- 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| Boxscore
Round 22
|- 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| Boxscore
Round 23
|- 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| Boxscore
Ladder
The NBL tie-breaker system as outlined in the NBL Rules and Regulations states that in the case of an identical win–loss record, the results in games played between the teams will determine order of seeding.
1Wollongong Hawks won Head-to-Head (2-0).
2Brisbane Bullets won Head-to-Head (2-1).
3Townsville Crocodiles won Head-to-Head (2-1).
4Sydney Kings won Head-to-Head (2-1).
Finals
Playoff bracket
Qualifying Finals
|- 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| Boxscore
Semi-finals
|- 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| Boxscore
Grand Final
|- 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| Boxscore
1998–99 NBL statistics leaders + Category Player Team Stat Points per game Andrew Gaze Melbourne Tigers 33.5 Rebounds per game Mark Bradtke Melbourne Tigers 12.0 Assists per game Darryl McDonald Victoria Titans 8.2 Steals per game Darryl McDonald Victoria Titans 8.2 Blocks per game Simon Dwight West Sydney Razorbacks 3.0 Free throw percentage Andrew Gaze Melbourne Tigers 89.4% Three-point field goal percentage John Rillie West Sydney Razorbacks 47.5%
NBL awards Most Valuable Player: Steve Woodberry, Brisbane Bullets Most Valuable Player Grand Final: Brett Maher, Adelaide 36ers Rookie of the Year: Damien Ryan, Canberra Cannons Best Defensive Player: Darnell Mee, Adelaide 36ers Best Sixth Man: Bruce Bolden, West Sydney Razorbacks Most Improved Player: C.J. Bruton, Wollongong Hawks Coach of the Year: Lindsay Gaze, Melbourne Tigers & Brendan Joyce, Wollongong Hawks
All NBL Team #PlayerTeam PG Steve Woodberry Brisbane Bullets SG Andrew Gaze Melbourne Tigers SF Lanard Copeland Melbourne Tigers PF Kevin Brooks Adelaide 36ers C Mark Bradtke Melbourne Tigers
External links NBL official website, including live scores and fixtures