The Campeonato Brasileiro Série B 2005, the second level of the Brazilian National League, was played from April 23 to November 26, 2005.
The two best ranked teams in each group advanced to the final round.
Those four teams were put into a single group, and played against each other home and away.
The Grêmio finished with the most points, advancing to the Série A along with Santa Cruz.
The six last ranked teams in the first round (Anapolina, Bahia, Caxias, Criciúma, União Barbarense and Vitória) were relegated to play the Série C in 2006.