During a career that lasted from 1993 to 2014 he played for the Pittsburgh Penguins, Vancouver Canucks, Dallas Stars, Atlanta Thrashers, and New Jersey Devils of the National Hockey League (NHL), as well as Leksands IF of the Swedish Elitserien, as well as several minor league teams.

He was told by the Flyers that he needed to make the Swedish national team, before getting an invitation to training camp.

He then left Sweden, in 1997, to find work in the North American minor leagues, hoping that a team would notice his abilities.

[2] He started with the Baton Rouge Kingfish of the East Coast Hockey League and also played for the Detroit Vipers and Manitoba Moose of the International Hockey League before the Flyers traded Hedberg's rights to the San Jose Sharks in 1998.

Hedberg excelled during his second stint with the Moose in 2000–01, while they were still an unaffiliated team in the final season of the International Hockey League.

In March 2001, Randy Carlyle, the Moose's coach, pulled Hedberg aside at Winnipeg International Airport and told him he'd been traded to Pittsburgh,[2] along with Bobby Dollas, in exchange for Jeff Norton.

[3] He then outdueled Olaf Kölzig, of the Washington Capitals, and Dominik Hašek, of the Buffalo Sabres, to help the Penguins reach the Eastern Conference final.

[1] He was then named as the back-up goalie to Tommy Salo, on the Swedish national team and played in the 2002 Winter Olympics.

[1] He was finally traded to the Vancouver Canucks by Pittsburgh for a second-round selection in the 2004 NHL Entry Draft.

[7] On 1 July 2010, Hedberg signed a one-year deal with the New Jersey Devils, which included a no-trade clause.

During round one of the 2012 Stanley Cup Playoffs, he was called on to play two periods in game three versus the Florida Panthers.

The Devils bought him out as a result of a trade that sent Vancouver Canucks goaltender Cory Schneider to New Jersey.

[9] Hedberg signed a professional tryout with the New York Rangers on 10 September 2013, in the absence of backup goaltender Martin Biron.