2005 Campeonato Gaúcho

The championship would have four stages:^[2][1]

• First stage: The 18 teams were divided into three groups of six teams each. They played against each other inside their groups in a double round-robin system. After 10 rounds, the top two teams of each group, plus the two best third-placed teams qualified to the Semifinals.
• Copa Emílio Perondi: The fourteen teams that didn't participate in the Série A or Série B were divided into 2 groups of seven teams each. They played against each other inside their groups in a double round-robin system. After 14 rounds, the two best teams in each group qualified to the Semifinals, the winners of which would qualify into the Finals, with the winner qualifying to the Série C of that year, and the bottom team in each group being relegated.
• Semifinals: The eight remaining teams were divided in 2 groups of 4 teams each and they played in a double round-robin system. The winner of each group qualified to the Finals.
• Finals: Semifinals group winners played in two matches to define the Champions. The team with best overall record played the second leg at home.