Camacho, 50, was taken off life support Saturday at a hospital where he had been treated since being shot in the head Tuesday in an incident that appeared to be drug related.
Dr. Ernest Torres of the Centro Medico trauma center said Camacho went into cardiac arrest and died shortly after the life-support system was shut off.
Camacho, a native of Puerto Rico who grew up in New York City, won championship belts in three weight classes in the 1980s and 1990s. He retired after losing to welterweight champion Oscar De La Hoya in 1997 at age 35.
Camacho came from a rough upbringing but enthralled the boxing world with not only his surgeon-like skills in the ring but his outlandish behavior in front of the media, The New York Times said.
He routinely had brushes with the law involving drug possession, domestic violence and an incident in which he tried to smuggle an M-16 rifle through customs, the Times said.
Funeral plans for Camacho were pending Saturday. He was survived by his mother, sister and four sons.