After two more seasons as a Bruin, playing with the likes of Ray Bourque, Cam Neely, and Adam Oates, Smolinski was dealt to the Pittsburgh Penguins where he joined such superstars as Mario Lemieux and Jaromir Jagr. The Pens made a run for the Cup in 1996 but was stopped by the underdog Florida Panthers that squeaked out a win in game seven of the conference finals.

A member of U.S. World Cup team in 1996, Smolinski sat out the beginning of the 1996-97 season in a contract dispute as the Penguins looked to deal the talented forward. Several teams bid for his services, but in the end the Islanders won out. Smolinski made an immediate impact on the team. He spent three seasons in New York before being traded to the Los Angeles Kings in 1999 where he played for parts of four seasons before being acquired by the Ottawa Senators at the March trading deadline in 2003.

As a Senator, Smolinski reached the 500-point plateau and represented Team USA at the 2004 World Cup of Hockey.

Smolinski would compete with the Senators for two seasons before being sent to the Chicago Blackhawks with Martin Havlat in exchange for Tom Preissing, Josh Hennessy, Michal Barinka and a 2nd round draft pick in the 2008 entry draft.

As a Blackhawk, Smolinski was one of the bright spots on a Chicago club that struggled throughout the 2006-07 season. Set to become an unrestricted free agent in the summer, the Blackhawks opted to trade the winger to the Vancouver Canucks in exchange for a 2nd-round pick one day prior to the NHL trading deadline. Smolinski appeared in 20 regular season, and 12 playoff games with the Canucks before signing a one year contract with the Montreal Canadiens in the off-season.

Aside from his World Cup experience, Smolinski is a two-time member of the U.S. World Championship team in 1998 and 1999.