The Ottawa Senators were the regular-season champion, but lost in the NHL playoff final to the Montreal Maroons.
At the annual meeting on November 7, 1925, the league added another new expansion franchise, in Pittsburgh, the third United States-based team in the NHL.
Nels Stewart not only set a record for goals by a first-year player, but became the first rookie to win the scoring title.
Ottawa's coach Curry was quite successful, as he took a team that had gone from fourth overall to first with an impressive record of 24–8–4, and the expansion Pittsburgh Pirates, with a strong cast of ex-amateurs led by future Hall of Famers Roy Worters and Lionel Conacher, finished third.
The Pirates introduced "on-the-fly" player substitution to the NHL, a practice already in use in the Western League.
[2] The first regular-season game at Madison Square Garden between the Montreal Canadiens and the expansion New York Americans was a big event.
Opening ceremonies included performances by the Governor General's Body Guard Band of Toronto and the United States Military Band from West Point, displays of 'fancy skating', a miniature game between the team's mascots and the opening faceoff was made by New York Mayor John F. Hylan and Tex Rickard.
Montreal won the game, officiated by Cooper Smeaton 3–1, and were awarded the new Prince of Wales Trophy.
The second seed Montreal Maroons beat the third seed Pittsburgh Pirates and then went on to beat first place Ottawa Senators two goals to one in a two-game total goals series, thus capturing the O'Brien Cup, Prince of Wales Trophy and the right to play the Victoria Cougars for the Stanley Cup.
Nels Stewart was "Old Poison" to the Victoria Cougars, as he scored six goals in the four games and goaltender Clint Benedict shut out the westerners three times.
Note: GP = Games played; G = Goals; A = Assists; Pts = Points Source: NHL.