He won two President's Cups coaching the Laval Voisins and the Verdun Junior Canadiens to QMJHL championships.

After he led a team from Sainte-Foy to a junior-B championship during the 1981–82 season, he was considered for the Shawinigan Cataractes coaching position.

[7] Future National Hockey League (NHL) players on the team were Joel Baillargeon, Yves Beaudoin, Alain Raymond, Serge Roberge and Sylvain Turgeon.

[6] His team included future NHL players Mario Lemieux, Vincent Damphousse, Bobby Dollas, Steve Finn, Yves Courteau, and Michel Mongeau.

[12] Before the tournament, Bégin was quoted as saying, "It will be the 66th Memorial Cup and I hope our #66 [Lemieux] will continue his output of the regular season and playoffs".

[14] Laval struggled without Lemieux who was now on the Pittsburgh Penguins in the NHL, and the Voisins were drawing an average crowd of only 750 fans per game.

[16] Bégin was named head coach of the Verdun Junior Canadiens for the final five games of the 1984–85 QMJHL season and the playoffs.

[17] The team included future NHL players Claude Lemieux, Jimmy Carson, Gerry Fleming, Shane MacEachern, and Everett Sanipass.

[18] Bégin led Verdun to three wins in the remainder of the regular season, and a first-place finish in the Lebel Division.

The Draveurs had three future NHL players, including Claude Lapointe, Donald Dufresne, and Frank Breault.

[22] Bégin relocated to France and became head coach of HC Amiens Somme for the 1986–87 Nationale 1A season.

[23][24] Bégin was named head coach and general manager of the Drummondville Voltigeurs for the 1987–88 QMJHL season.

[25] His team included future NHL players Frédéric Chabot, Rob Murphy, Claude Boivin, Daniel Doré, and Mario Doyon.

[26] On November 6, 1987, he was announced as an assistant coach to Dave Chambers on the Canada men's national junior ice hockey team, to replace Clément Jodoin who joined the Pittsburgh Penguins.

Canadian author Gare Joyce described Bégin as the easy-going part of the "good cop/bad cop" duo of the team's assistant coaches, compared to Ken Hitchcock.

[25][29][30] During the tournament, he was given an interview by Hockey Canada for the national junior team head coach position at the upcoming 1989 World Championships.

[14] On February 9, 1989, Bégin was suspended indefinitely as coach and general manager of the Drummondville Voltigeurs, after he was arrested on accusations of sexual assault.

Lupien stated the player's initial complaints were, "the coach always wants a private meeting with me after every practice, and he talks about all kinds of things, but never hockey".

[35] At the sentencing hearing, Bégin wept as he told the court that he had been sexually abused as a youth and considered himself to be deeply scarred.