Sen. Pierre-Hugues Boisvenu made the remarks in Ottawa before the upper chamber began debate on a crime reform bill, the Canadian Broadcasting Corp. reported.
"Basically I think that every murderer should have a rope in his cell and he can decide on his own life," he said. "But I'm against the [state] death penalty."
He also spoke of several notorious Canadian serial killers and criticized the millions of dollars spent to keep them in prison.
His remarks caused an immediate firestorm of criticism from opposition parties and the senator quickly made several French-language media appearances, telling one television network he "spoke too hastily," The (Montreal) Gazette reported.
The Quebec senator founded a victims' rights group after his daughter was murdered in 2002.