As always the regular season saw several surprises. The San Jose Sharks, who many felt would be one of the elite teams in the West, stumbled early and badly and disassembled much of the team. The two-year-old Minnesota Wild, on the other hand, got out to an early start and held onto their first ever playoff berth throughout the season, winning coach Jacques Lemaire the Jack Adams Award.
The most surprising team was perhaps the Tampa Bay Lightning, which many had predicted to finish last, contesting for the Southeast Division title and making the playoffs for the first time in seven years. The most disappointing teams, other than the Sharks, were the New York Rangers, who finished out of the playoffs again despite bearing the league's leading payroll, and the Carolina Hurricanes, who finished last overall after a surprise run to the Stanley Cup Finals the year before.
At the midpoint of the season the Canucks lead the Western Conference, and Ottawa lead the East. Vancouver stumbled somewhat over the stretch and lost the Northwest Division title to Colorado and the Western Conference one to Dallas. Ottawa continued to dominate, having the best season in franchise history and winning both the Eastern Conference and the Presidents' Trophy.
The season was also marred by financial difficulties. Despite their success the Ottawa Senators were in bankruptcy protection for almost all of 2003, and at one point could not pay the players. Owner Rod Bryden tried a variety of innovative financing strategies, but these all failed and the team was purchased by billionaire Eugene Melnyk. The Buffalo Sabres also entered bankruptcy protection before being saved by New York businessman Tom Golisano. The financial struggles of the Pittsburgh Penguins continued as the team continued to unload its most expensive players.
Worries over the decline in scoring and the neutral zone trap continued. The season began with an attempted crack down on obstruction and interference, but by the midpoint of the season this effort had petered out. The expansion teams in the southern United States began to suffer financially, with many empty seats to be found in each arena. Most teams lost money on the season. The one bright spot was the increasing value of the Canadian dollar, which made the six Canadian teams more competitive than they had been in years.
The second round in the west brought more upsets. The Minnesota Wild again fell 3–1 behind while playing Vancouver, but rallied and defeated them in seven games. Giguere's stellar goaltending continued to triumph as the Ducks ousted the Stars in six games. The Western Conference final was a meeting of two dark horse teams, but the superb goaltending of Giguere and the Ducks triumphed over the tight checking of the Minnesota Wild.
The east was far more predictable as Tampa Bay's youth showed when playing the grizzled veterans of the New Jersey Devils and the Ottawa Senators dispatched a tired Flyers team for the second year in a row. The Eastern Conference finals were a contrast of styles between the offensively explosive Senators and the defense minded Devils. The Devils came out to an early lead in the series, Ottawa rallied, winning games five and six on the energizing play of rookie Jason Spezza, but then the Devils regained their form as goaltender Martin Brodeur helped them win game seven and advance to the Stanley Cup finals for the third time in four years.
The Stanley Cup finals were a duel between two elite goaltenders, but after seven games the Devils triumphed to win their third Cup in seven years. The series also saw Scott Stevens land one of his prototypical crushing hits on Anaheim captain Paul Kariya, similar to the one that had knocked out Eric Lindros, then of the Flyers in the 2000 Playoffs. Unlike Lindros, Kariya returned to the game only ten minutes later and scored.