The 2003–04 LEB 2 season was the 4th season of the LEB Plata, second league of the Liga Española de Baloncesto and third division in Spain.

14 teams play the regular season.

This is a round robin, where each team will play twice against every rival.

After the regular season, the eight first qualified teams played a playoff, were the two finalists promoted to LEB.

If two or more teams have got the same number of winning games, the criteria of tie-breaking are these: