He played in the National Hockey League (NHL) for the Calgary Flames, Toronto Maple Leafs and Washington Capitals.

He also played for Djurgårdens IF and Brynäs IF of the Elitserien, as well as Severstal Cherepovets and Lokomotiv Yaroslavl in the Kontinental Hockey League (KHL).

[1] Kronwall scored his first and only NHL goal on October 6, 2009, in a 4–3 win against goaltender Jaroslav Halák of the Montreal Canadiens,[3] but spent the majority of the season with the AHL's Abbotsford Heat.

[7] Kronwall represented Sweden at the 2002 World Junior Ice Hockey Championships, where he was pointless in seven games.

At the 2011 IIHF World Championship, he recorded one goal and three assists in nine games and won a silver medal.