His death was announced by his agent Thursday who BBC News reports said "He died peacefully at his LA home surrounded by his family. Privacy is asked for at this very sad time." He died following a five-year struggle with cancer.
Fans of the actor, who was a huge hit in the 70's, will want to mark his passing though.
Bodie and Doyle, the cop duo played by Collins and Martin Shaw respectively, were the TV heartthrobs of the day. Their characters were tough and attracted as many male fans as females. Collins will be remembered as a handsome hunk rather than for his acting career.
Professional co-star Martin Shaw told BBC News he was sad to learn of Collins death saying: "He will be remembered as part of the childhood of so many people, and mourned by his fans. I send my love and condolences to his family, and the great many who will miss him".
Collins starred in the movie Who Dares Wins in 1982 playing the role of SAS captain Peter Skellen. In the same year he auditioned for the role of James Bond but his acting style was deemed "too aggressive".
Lewis tended to play tough roles and early in his acting career appeared in UK TV series Z Cars and The New Avengers. However he also had a long standing role in a TV sit-com The Cuckoo Waltz.
Fellow "Professional" Martin Shaw has enjoyed a long and successful acting career but Collins was not so lucky. The Professionals was the peak of his career. Other roles that followed were minor by comparison.
Lewis Collins married in 1992. He is survived by his wife Michelle and three sons.