Tom Barrasso was drafted fifth overall in the 1983 Entry Draft by the Buffalo Sabres. That year, Tom made his NHL debut on October 5 with a 5-3 victory on opening night against the Whalers. In that rookie season, he split goaltending duties with Bob Sauvé and helped the Sabres improve 14 points in the standings to 48 wins and 103 points. Tom was 26-12-3 in his 42 games and finished second in the league with a 2.84 goals-against average. He won the Calder Trophy (top rookie) and Vézina Trophy (top goalie) and was named to both the First All-Star Team and All-Rookie Team. In 1984-85, Tom played 54 games and paced the league with five shutouts and a 2.66 GAA. He was voted to start in the mid-season All-Star Game, was a Second Team All-Star and shared the Jennings Trophy with Sauvé. He was also runner-up to the Vézina Trophy.
In 1985-86, Tom posted a 29-24-5 record in 60 games as the club's number-one goalie ahead of Jacques Cloutier. In 1986-87, Tom played 46 games and posted a 17-23-2 record. In 1987-88, Tom went 25-18-8 as the team improved 19 points to make the playoffs for the first time in three years. Tom won Player of the Month honours in January and was the runner-up at year's end to the Vézina Trophy.
In 1988-89, Tom was traded on November 12 with a third-round draft pick to the Pittsburgh Penguins for Doug Bodger and Darrin Shannon. After playing ten games with the Sabres, Tom posted a 18-15-7 record in 44 games with the Penguins. His play helped the Penguins reach the playoffs for the first time in seven years. In 1989-90, Tom played just 24 games as he missed 23 games at the start of the season with a broken wrist (injured October 14) and 29 games at the end of the season on a leave of absense. The Penguins fell 15 points in the standings and missed the playoffs. In 1990-91, Tom went 27-16-3 in 48 games as the Penguins bounced back 16 points to win the Patrick Division season title and make the playoffs. Tom won Player of the Month honours in December. In the post-season, Tom led the Penguins to both the Prince of Wales Trophy and Stanley Cup. His 2.60 GAA paced all playoff goalies.
In 1991-92, Tom went 25-22-9 in 57 games as the Penguins fell to third in the Patrick Division standings (they dropped from 88 to 87 points). In the playoffs, however, Tom helped the Penguins knock off the Capitals (second in their division) and Rangers (first in the league) in the first two rounds. Tom and the Penguins then swept the Bruins to win the Prince of Wales Trophy and the Blackhawks to win the Stanley Cup. Tom paced all post-season goalies with 21 games, 1,233 minutes played and, most importantly, 16 wins.
In 1992-93, Tom was a Second Team All-Star with a league-best 43 wins. He led the Penguins to a 22-point improvement to win the Patrick Division season title and the Presidents' Trophy. On November 20, Tom passed Denis Herron (88) as the team's all-time wins leader. By season's end, Tom had tied the club's single-season games-played record by a goaltender (63, first set by Greg Millen) and broken the team records for wins, wins at home (24), wins on the road (19), winning percentage (73.4%) and assists (8). He also set a team record with 14 straight wins and helped the Penguins set a league record with 17 straight wins. He was the year-end runner-up to the Vézina Trophy while his 3.01 GAA ranked third in the league and his 90.1 save percentage ranked fourth. In the post-season, Tom won the first three games of the opening round against the Devils to set a league record with 14 straight playoff wins. The Penguins reached the second round that year before losing to the Islanders.
In 1993-94, Tom went 22-15-5 as the Penguins won their third division title (now the Northeast) in four years. On February 15, Tom broke Frank Brimsek's all-time record (252) for wins by an American-born goaltender. In the shortened 1994-95 season, Tom missed all but two games recovering from wrist surgery as the Penguins fell to second in their division. In 1995-96, Tom went 29-16-2 as the Penguins recaptured the Northeast Division title. In the playoffs, Tom helped the Penguins reach the second round.
In 1996-97, Tom was limited to just five games as he spent nearly all of the season on the sidelines with a shoulder injury. The Penguins fell 18 points in the standings to finish second in the Northeast Division. In 1997-98, he returned healthy and posted a 31-14-13 record as the Penguins bounced back 14 points to again win the Northeast Division title. Tom tied his team record of 63 games by a goaltender and set club records with a 2.07 GAA and seven shutouts. His 92.2 save percentage ranked tied for second in the league. On October 19, Tom recorded his 300th win in a match against the Panthers. In 1998-99, Tom played 43 games and posted a 19-16-3 record with a 2.55 GAA. On January 5, Tom recorded a pair of assists against the Flames to pass Grant Fuhr as the league's all-time assists leader amongst goaltenders. He also recorded the win to move into tenth place on the all-time wins list past Gump Worsley (335). On February 21, he played in his 700th game. In the playoffs, Tom helped the Penguins reach the second round.
In 1999-2000, Tom was traded on March 14 to the Ottawa Senators for Ron Tugnutt and Janne Laukkanen. He left the club as the team's all-time leader in games by a goaltender (458), wins (226), losses (153), ties (53), saves (12,064) and shutouts (22). In 25 games between the two teams, Tom posted a 8-11-2 record.
After a year away from hockey, Tom signed as a free agent with the Carolina Hurricanes on July 17, 2001.
