Lewis was to become an unrestricted free agent next week. But the Browns, who went 10-6 and barely missed the playoffs last season, didn't want to risk losing the bruising back after he rushed for more than 1,300 yards.
"The Browns are pleased that Jamal has decided to continue his career here in Cleveland," general manager Phil Savage said in a statement. "He brings a maturity, toughness and football temperament to the team that is critical to our success on top of the physical abilities that he possesses."
Lewis proved he could be an effective every-down back in 2007. After signing a one-year, incentive-laded free-agent deal in March, he gained 1,304 yards and scored nine touchdowns. Only Hall of Famer Jim Brown has run for more yards in a season for the Browns.
Lewis came to Cleveland after seven years in Baltimore. At the time he signed, there were questions about Lewis' durability and speed, but he answered them all with his best season since leading the NFL with 2,066 yards in '03.
In doing so, Lewis validated Savage's belief the former first-round draft pick still could be productive. The two worked together for five years in Baltimore.
"I am thankful to the Browns for the opportunity they gave me last year to come out and prove that I was still one of the top running backs in the NFL," Lewis said in a statement released by the team. "I feel the future is extremely bright for this team and I'm excited to be a part of it for another three years."
Behind Cleveland's revamped offensive line, Lewis ran with the same brutal tenacity that helped him gain 7,801 yards with the Ravens. He underwent surgery to remove bone spurs in his ankle in the offseason, which seemed to give Lewis back some lost quickness.
Following the comeback season, Lewis said he liked Cleveland and wanted to remain with the Browns, who won a club record seven home games and were kept out of the AFC playoffs only by a tiebreaker.
"I said all year long that I wanted to get a long-term deal done to stay in Cleveland and it looks like with this new contract I will be able to finish my career as a Brown," Lewis said.
In addition to performing beyond expectations, Lewis counseled younger players, who were impressed by his tireless work ethic.
"Jamal has matured quite a bit since he's come into the league," Savage said following the season. "He's been an excellent leader quietly behind the scenes. He's a real pro and takes care of himself."
With Lewis under contract, Savage can turn his attention to quarterback Derek Anderson.
Savage will meet in Indianapolis with Anderson's agents about completing a long-term deal before Anderson can become a restricted free agent. The Browns have offered Anderson a three-year deal and Savage is optimistic an agreement can be reached before the 24-year-old hits the market.
Anderson made the Pro Bowl following a breakout 2007 season. He threw 29 TD passes after starting the season as Charlie Frye's backup.