Didier Pitre's first major hockey league was in an early IHL playing with the Michigan Soo Indians, who played in Sault Ste. Marie, Michigan. He joined the Soo team in 1904. By 1905/06, he was the already the top scorer in the league scoring 41 goals in 22 games played. Pitre was on the IHL all-star first team that year in 1906 and again in 1907.
Shamrocks
The next season, he left as a free agent and played with the Montreal Shamrocks in the Eastern Canada Amateur Hockey Association. He lasted only one year before leaving to play with the Edmonton Eskimos. He stayed three games with the Eskimos before jumping contract and coming back to eastern Canada where he played with the Renfrew Creamery Kings for the remainder of 1908.
Canadiens
He joined the Montreal Canadiens in 1909. He stayed for four years, before leaving for the west again. He spent a year playing with the Vancouver Millionaires. Pitre returned to Montreal the next year. In 1916, Pitre led the National Hockey Association in regular season assists and points. He scored 24 goals, 15 assists for 39 points. He also helped lead the Canadiens to their first ever Stanley Cup. He led the playoffs in goals as well. In the 1919 Stanley Cup playoffs, which were never completed due to the influenza epidemic, he led the playoffs in points. By 1921, the Canadiens had so much depth at forward, and an opening on defence due to the death of future Hall of FamerJoe Hall in the influenza epidemic, so they decided to try Pitre as a defenceman; not as difficult a transition as one might think, because he had previously been a "Rover" during the days of "seven man" hockey. He remained with Montreal through the formation of the NHL and into 1923.
Last seasons
A forward throughout his career, Pitre played the final two as a defenceman. His nephew, Vic Desjardins, would also play in the NHL and would be inducted into the United States Hockey Hall of Fame. Didier Pitre was also a member of the great line called "The Flying Frenchmen" alongside of Jack Laviolette and Edouard "Newsy" Lalonde. He died July 29, 1934 as a result of acute indigestion. As was customary of the time period, heart attacks were often mistakenly diagnosed as indigestion. Pitre likely died as a result of a mis-diagnosed heart attack. In 1963 he was inducted into the Hockey Hall of Fame.