The 1999–2000 CBA season was the fifth CBA season. The season ran from November 21, 1999, to March 19, 2000. Nanjing Army Thunder and Hubei Mailyard were promoted from the Second Division. Vanguard from the Second Division was merged with Beijing Olympians and the club was known as Vanguard Beijing Olympians for the next several seasons.

Regular season standings

Playoffs

The top 8 teams in the regular season advanced to the playoffs. In the Final series, Bayi Rockets defeated Shanghai Sharks (3-0), and claimed its 5th straight CBA championship. Teams in bold advanced to the next round. The numbers to the left of each team indicate the team's seeding in regular season, and the numbers to the right indicate the number of games the team won in that round. Home court advantage belongs to the team with the better regular season record; teams enjoying the home advantage are shown in italics.

Relegations

The bottom 4 teams played the relegation round by round-robin. Nanjing Army Thunder and Hubei Mailyard were relegated to the Second Division.