He has also played for the Boston Bruins, Pittsburgh Penguins, Washington Capitals, Detroit Red Wings, Chicago Blackhawks, Montreal Canadiens and Phoenix Coyotes, with whom he retired with in 2010.

A native of Czechoslovakia, Lang began his career in the Czechoslovak Extraliga as an eighteen-year-old with HC Litvínov.

Due to the lockout-shortened 1994–95 season, Lang returned to HC Litvínov (now of the Czech Extraliga) for 16 games, scoring 23 points.

After a brief hiatus from the NHL, Lang returned after one season in Europe, joining the Pittsburgh Penguins as a free agent on September 2, 1997.

[1] Lang remained with the Penguins, joining fellow Czech Jaromír Jágr and increasing his points total in each of his first four seasons with the team.

Lang returned to the Red Wings in time for the 2004 playoffs, but the team was eliminated by the Calgary Flames in the second round.

Before signing a two-year contract with the Chicago Blackhawks as an unrestricted free agent in the off-season,[6] Lang embarked on another playoff run with the Red Wings in 2007, but they were halted by the eventual Stanley Cup champions Anaheim Ducks in the semifinals.

After just one season with the Blackhawks, he was traded to the Montreal Canadiens for a second-round draft pick in 2010 (previously acquired from the Toronto Maple Leafs) on September 12, 2008.

[7] Lang recorded a natural hat-trick, the second three-goal effort of his career, in his first season with the Canadiens, against the New York Rangers on January 7, 2009, in a 6–3 win.

On September 29, 2009, Lang was signed by the Phoenix Coyotes to a one-year contract, just days before the start of the 2009–10 season.

The following year, Lang competed in the 1997 World Championships, defeating Russia in the bronze medal game.

In 1998, Lang competed in his second Winter Olympics, capturing gold on a team with Dominik Hašek and Pittsburgh Penguins teammate Jaromír Jágr.

Lang scored three points in four games, but the Czechs were kept from defending their gold medal, falling to Russia in the quarterfinals.