The football (soccer) Campeonato Brasileiro Série B 2004, the second level of Brazilian National League, was played from April 23 to December 11, 2004.
The eight best ranked teams advanced to the second round, where they were divided in two groups of four.
Those four teams were put in a single group, and played against each other home and away.
Brasiliense finished the final phase group with most points and was declared 2004 Brazilian Série B champions, claiming the promotion to the 2005 Série A along with Fortaleza, the runners-up.
The six worst ranked teams in the first round (América-RN, Remo, América Mineiro, Joinville, Mogi Mirim and Londrina) were relegated to play Série C in 2005.