At dissolution, the 125 seats of the National Assembly were distributed as follows:
</center><br>
Liberal member Daniel Bouchard (Megantic-Compton) is sitting as an independent while being under an inquiry relating to a former job.
Liberal member Russell Williams (Nelligan) resigned on March 9, 2004. Yolande James (PLQ) won the by-election with 52.6% of the vote.
Liberal member Marc Bellemare (Vanier) resigned on April 28, 2004. Sylvain Légaré (ADQ) won the by-election with 46.8% of the vote.
Liberal member Christos Sirros (Laurier-Dorion) resigned on June 17, 2004. Elsie Lefebvre (PQ) won the by-election with 46.1% of the vote.
Parti Québécois member André Boisclair (Gouin) resigned on August 17, 2004. Nicolas Girard (PQ) won the by-election with 57.8% of the vote.
By-elections were held in these four districts on September 20, 2004.
Libéral member Yves Séguin (Outremont) resigned on May 26, 2005. Raymond Bachand (PLQ) won the by-election with 48.8% of the vote.
Leader of the Opposition and Former Premier Bernard Landry (Verchères) resigned on June 6, 2005. Stéphane Bergeron (PQ) won the by-election with 69.2% of the vote.
By-elections were held in these two districts on December 12, 2005.
Parti Québécois member André Boulerice (Sainte-Marie-Saint-Jacques) resigned on September 12, 2005. Martin Lemay (PQ) won the by-election with 41,2% of the vote.
A by-election was held in this district on April 10, 2006.