The 28-year-old forward was traded to the Chicago Blackhawks on Saturday for defenceman Jassen Cullimore and forward Tony Salmelainen.
Samsonov, a Moscow native, signed as a free agent with the Canadiens last summer, but had just nine goals and 17 assists in 63 games.
The former two-time 29-goal scorer was a healthy scratch for 18 games - including the last 13 games after he questioned whether he made the right move in signing with the team.
Samsonov has one season at US$3.5 million left on his contract.
General manager Bob Gainey said after the season Samsonov would not be back.
"Considering we didn't have plans for Sergei Samsonov in our organization for next season, our options were either to buy out his contact or to trade him in order to allow us to save valuable cap room over the next two seasons," Gainey said in a release.
It is the second time Gainey has succeeded in finding a taker for a player he signed to large contract and then didn't want. In 2006, he unloaded the final two years of goaltender Jose Theodore's $16-million, three-year deal on the Colorado Avalanche for goalie David Aebischer.
Samsonov has 178 goals and 240 assists for 418 points in 596 career NHL games with Montreal, Edmonton and Boston.
"We believe Sergei can rebound and give us a spark on the power play and offensively as well as improve our overall skill level," Blackhawks GM Dale Tallon said in a release.
"We feel he has a lot left in the tank and playing under Denis Savard will bring out the offensive creativity that he has shown in the past."
Samsonov was selected by the Bruins with the eighth overall pick of the 1997 NHL entry draft. The former rookie of the year also has 13 goals and 26 assists in 59 career playoff games.
The trade was little more than a salary dump for the Canadiens.
Cullimore, who played 52 games for Montreal in the mid-1990s, is set to earn $1.9 million next season and the Canadiens say they have agreed to buy out his contract.
Salmelainen earns $750,000 next year and the team says his situation will be evaluated in the coming weeks.
Cullimore had two goals and 12 assists in 118 games over the last two seasons with the Blackhawks. The six-foot-five, 220-pounder has 21 goals and 59 assists over 643 career games.
He won a Stanley Cup with the Tampa Bay Lightning in 2004.
Salmelainen, 25, had six goals and 11 assists in 57 games with the Blackhawks last season.