2003–04 Croatian First League

In the first part of the season, 16 teams played single-circuit league (15 matches).

After 15 rounds the first six teams qualified for the Championship play-offs - playing for the Championship title and the remaining 10 in the Relegation play-offs - playing to stay in the league.

[1] Intermediate matches from the first part of the championship were transferred, and the clubs played three more times (15 matches).

[2] [2] Relegation play-offs determined the placement of clubs that were between 7th and 16th place in the first phase of the championship.

18 matches were played (double league system).