General manager Peter Chiarelli announced Friday that Lewis will be relieved as head coach and reassigned to another position in the organization. Associate coach Marc Habscheid also will be reassigned.
"Since the season has ended I have completed a thorough review of the team and the coaching staff, and I have determined that Dave Lewis and Marc Habscheid are not the proper fit for the Bruins at this time," Chiarelli said, before adding: "I have a short list of candidates in mind."
Lewis was 35-41-6 in his lone season on the Bruins' bench. He also was the head coach in Detroit from 2002-04, where he had a 96-41-21-6 record.
The Bruin haven't won the Stanley Cup since 1972 and have missed the playoffs in each of the past two seasons.
"Having come from organizations where you're used to winning, that's been very difficult," Chiarelli said after the season. "But I also know quick fixes don't work and so I have to be patient. I have to balance the two things because I know our ownership demands a winner and I know the city demands a winner."
Chiarelli was the assistant general manager of the Ottawa Senators last season, when they finished second in the NHL with 113 points. Lewis was an assistant coach on three of Detroit's Stanley Cup-winning teams.
Chiarelli wouldn't put a timetable on finding a new head coach, but said it was important to find someone before July 1, when the free-agent period begins.
The Bruins underwent a major housecleaning last summer, bringing in Chiarelli and Lewis. They flirted with the playoff race for a while but went 1-10-1 in their last 12 games and played shoddy defence, allowing 289 goals - the second most in the league.
Inconsistency was Lewis's undoing, with the Bruins going through hot and cold stretches throughout the season.
"We'd go for long stretches of good play and then we'd have long stretches of poor play," said Chiarelli. "I don't expect top level play all the time, but I do expect consistency."
Boston also was short on offence with 217 goals, seventh fewest in the league.
Chiarelli said with several weeks remaining in the season that Lewis would return for a second season. "We've moved along the learning curve and you just can't throw that away," the GM said then.
Lewis said after the season that his history with the Red Wings may have blinded him to the work that needed to be done.
"I probably took a number of things for granted that I shouldn't, thinking that the players understand," he said then. "Where I came from, it's just sort of natural, which it really isn't natural. It's a learned process, so that's where I have to improve."
Lewis was hired by Boston on June 29, 2006. Prior to joining the team, he served as head coach of the Detroit Red Wings from 2002-2004, where he amassed a record of 96-41-21-6.
Habscheid was hired last July after spending a couple years coaching Canada's national men's team.