Lehman began his playing career in 1903–04, playing for the Pembroke Lumber Kings of the Ottawa Valley Hockey League (OVHL) for the first three seasons of his career.
In the 1906–07 season, Lehman was signed as a free agent by the Canadian Soo of the International Professional Hockey League (IPHL); the IPHL was the first fully professional ice hockey league.
Lehman returned to Pembroke for the 1907–08 season, appearing in four games.
For the 1908–09 season, Lehman joined the Berlin Dutchmen of the Ontario Professional Hockey League (OPHL).
In the 1909–10 season, Lehman was in two different Stanley Cup playoff series, with two different teams, the Berlin Dutchmen and the Galt Professionals, but he lost both times.
During those playoff series, he appeared in three games, giving up 22 goals.
Lehman played with the Berlin Dutchmen until 1911.

In 1911–12, Lehman played for the New Westminster Royals of the newly founded Pacific Coast Hockey Association (PCHA).
He played three seasons for New Westminster, winning the league championship in his first season.
In 1914–15, Lehman joined the Vancouver Millionaires of the PCHA.
In his first season with the Millionaires, Lehman posted a 14–3 record, with a 4.08 goals-against average, which was a very good average in an era when goaltenders were not allowed to drop on their knees to make a save.
In the Stanley Cup playoffs, Lehman helped the Millionaires become the first PCHA team to win the Stanley Cup, with a 3–0 record and 2.67 goals against average.
This would be the only Stanley Cup victory of Lehman's career, as he was on the losing side in seven other attempts.
The Millionaires squad consisted of seven future members of the Hockey Hall of Fame when they won the Cup: Lehman, Frank Nighbor, Cyclone Taylor, Si Griffis, Barney Stanley, Frank Patrick, and Mickey MacKay.

Lehman played with the Millionaires until the 1925–26 season.
During that time, Lehman and some of his teammates were involved in a humorous incident when going back to Canada after an exhibition game against the Montreal Wanderers in New York City.
In New York, Lehman's wife bought numerous women's designer outfits, after being treated to a shopping spree by him.
When going back to Canada, Lehman, on the advice of Cyclone Taylor, who was both a professional ice hockey player and a Canadian immigration officer, split up all outfits among his teammates to avoid paying additional taxes he would have had to pay if he had brought all the clothing by himself at once; this puzzled the Customs officers.
In 1922–23, the Millionaires were renamed the Maroons, and joined the Western Canada Hockey League (WCHL).
The WCHL was renamed to the Western Hockey League in 1925–26; however, the league disbanded at the conclusion of that season.
While playing for the Millionaires, Lehman appeared in six Stanley Cup finals, losing every time, except in his first season, in 1914–15.

Following the collapse of the WHL, Lehman joined the Chicago Black Hawks for the 1926–27 season.
While in Chicago, Lehman mentored future Chicago goaltender and captain Charlie Gardiner.
Lehman played one full season, and another four games the next one.
 During the 1926 season, Lehman became the oldest goaltender to win his first NHL game at 41 years 21 days.
This record was broken on February 22 2020 by David Ayres who at 42 years, 194 days came into a game as an emergency backup goaltender for the Carolina Hurricanes against the Toronto Maple Leafs at Scotiabank Arena in the 2nd period and won the game 6-3.
Lehman began his playing career in 1903–04, playing for the Pembroke Lumber Kings of the Ottawa Valley Hockey League (OVHL) for the first three seasons of his career. In the 1906–07 season, Lehman was signed as a free agent by the Canadian Soo of the International Professional Hockey League (IPHL); the IPHL was the first fully professional ice hockey league. Lehman returned to Pembroke for the 1907–08 season, appearing in four games. For the 1908–09 season, Lehman joined the Berlin Dutchmen of the Ontario Professional Hockey League (OPHL). In the 1909–10 season, Lehman was in two different Stanley Cup playoff series, with two different teams, the Berlin Dutchmen and the Galt Professionals, but he lost both times. During those playoff series, he appeared in three games, giving up 22 goals. Lehman played with the Berlin Dutchmen until 1911.
In 1911–12, Lehman played for the New Westminster Royals of the newly founded Pacific Coast Hockey Association (PCHA). He played three seasons for New Westminster, winning the league championship in his first season. In 1914–15, Lehman joined the Vancouver Millionaires of the PCHA. In his first season with the Millionaires, Lehman posted a 14–3 record, with a 4.08 goals-against average, which was a very good average in an era when goaltenders were not allowed to drop on their knees to make a save. In the Stanley Cup playoffs, Lehman helped the Millionaires become the first PCHA team to win the Stanley Cup, with a 3–0 record and 2.67 goals against average. This would be the only Stanley Cup victory of Lehman's career, as he was on the losing side in seven other attempts. The Millionaires squad consisted of seven future members of the Hockey Hall of Fame when they won the Cup: Lehman, Frank Nighbor, Cyclone Taylor, Si Griffis, Barney Stanley, Frank Patrick, and Mickey MacKay.
Lehman played with the Millionaires until the 1925–26 season. During that time, Lehman and some of his teammates were involved in a humorous incident when going back to Canada after an exhibition game against the Montreal Wanderers in New York City. In New York, Lehman's wife bought numerous women's designer outfits, after being treated to a shopping spree by him. When going back to Canada, Lehman, on the advice of Cyclone Taylor, who was both a professional ice hockey player and a Canadian immigration officer, split up all outfits among his teammates to avoid paying additional taxes he would have had to pay if he had brought all the clothing by himself at once; this puzzled the Customs officers. In 1922–23, the Millionaires were renamed the Maroons, and joined the Western Canada Hockey League (WCHL). The WCHL was renamed to the Western Hockey League in 1925–26; however, the league disbanded at the conclusion of that season. While playing for the Millionaires, Lehman appeared in six Stanley Cup finals, losing every time, except in his first season, in 1914–15.
Following the collapse of the WHL, Lehman joined the Chicago Black Hawks for the 1926–27 season. While in Chicago, Lehman mentored future Chicago goaltender and captain Charlie Gardiner. Lehman played one full season, and another four games the next one.  During the 1926 season, Lehman became the oldest goaltender to win his first NHL game at 41 years 21 days. This record was broken on February 22 2020 by David Ayres who at 42 years, 194 days came into a game as an emergency backup goaltender for the Carolina Hurricanes against the Toronto Maple Leafs at Scotiabank Arena in the 2nd period and won the game 6-3.
Hughie Lehman