Forty clubs competed, four of which eventually qualified for the Campeonato Brasileiro Série C to be contested in 2013.
The 40 teams were divided in eight groups of 5, playing in a double round-robin format.
The two best ranked in each group at the end of 10 rounds qualified for the second stage, which was played in home-and-away system.
Rio Grande do Sul: Cerâmica replaced Veranópolis Esporte Clube, Novo Hamburgo, São José (PA), Pelotas and Lajeadense.
No Goias-based team wanted the berth so it passed on to the Federal District.