Before the start of the season, the league was divided into two seasons (north and south) of sixteen teams each. The season was played in the respective season in the mode "everyone against everyone" with a return game. The champions of the two seasons rose to the basketball Bundesliga 2005/06 , while the two worst teams in the final table were relegated to the respective regional leagues.
Season Notes
The end of the previous season 2. Basketball Bundesliga 2003/04 was marked by legal skirmishes for the status of players of foreign origin. As an innovation for the 2004/05 season with regard to this question, on the one hand the regulation came into force that there should no longer be any restrictions for players who have citizenship from a country of the European Union (EU) and from countries for which a corresponding nationality should apply Association agreement with the EU applies, so-called " Cotonou foreigners". On the other hand, the limit for all players with another nationality, for example those from the United States , was increased to a maximum of two per team. This hotly debated regulation also applied in the first national basketball league and was later relaxed even further before positive odds were introduced in the first division in 2011 after the ProA and ProB had preceded it.
The championship in Group North was decided by a direct comparison , in which the Eisbären Bremerhaven won six basket points after the two-way leg against the Paderborn Baskets .
Conversely, in the south group, three basket points decided who was relegated in a direct comparison. Newcomer Bayern Munich “lost out” to TSG Ehingen .