Les Castors de Montreal was formed in 1975 by shoe factory owner Tony Iammatteo. They joined the National Soccer League second division the same year. Iammatteo imported former Serie A player Gilberto Noletti and Brazilian star Cane (Jarbas Faustinho) to lead his team. After winning 12 games in a row they lost at home to Toronto Italia on August 31 in front of 4,000 fans. Alan Hopes was the leading goal scorer in the Second Division. Les Castors forfeited their promotion-relegation series to St. Catharines Heidelberg due to injuries and import players returning home.
1977 Montreal Castors won the league with two points. Hugo Nicolini was their player-coach.
Started the 1978 by being unbeaten in their first 10/11/12 matches.
After winning the league championship the Castors decided not to take part in the play-offs or the NSL Cup. Despite the success on the field, the club lost almost $250.000 in 1978. They averaged about 1,000 for their home league games. The club spent heavily to build a strong team only to see their best players depart to the NASL without the club recieving any compensation. Owner Tony Iammatteo applied for a franchise in the North American Soccer League but this was rejected by the NASL. After the season Montreal Castors asked for a one-year leave of absence from the NSL but never returned.
After the 1978 season Renato Cila, Pat Ercoli and Branko Segota joined the Rochester Lancers of the North American Soccer League. Branko Segota later played with New York Arrows in the Major Indoor Soocer League. Gordon Wallace joined Toronto Blizzard of the North American Soccer League.