Doctors were still performing tests before meeting with his family, said Ernesto Torres, the director of the Centro Medico hospital in Rio Piedras, Puerto Rico where Camacho was taken after Tuesday's shooting.
"Clinically, Hector 'Macho' Camacho is brain dead," the doctor said, adding that it will be up to the family to decide whether to disconnect the respirator keeping the boxer alive, he added at the press conference.
The announcement came around 30 hours after 50-year-old Camacho was shot while in a car in San Juan by people in another vehicle outside a liquor store.
Comacho's driver, Alberto Mojica Moreno, 49, was killed in the shooting.
It was unclear if they were targeted or simply caught in a random act of violence.
Torres had said earlier the bullet "damaged three arteries that run through the neck and as a result blood is not flowing well" to Camacho's brain.
Camacho, originally from Puerto Rico, was one of the most colorful boxers of the 1980s.
He has a career record of 79-6-3 with 38 knockouts, and over his career he took on all comers, including big names like Oscar De La Hoya, Julio Cesar Chavez, Sugar Ray Leonard, Felix Trinidad, Ray Mancini and Greg Haugen.
Earlier this year, US police charged Camacho with child abuse for allegedly slamming his son into a floor at his ex-wife's home in Florida. He was accused of hitting and stomping on his son, police documents say.
The incident took place on March 22, 2011, allegedly over money Camacho apparently believed was missing at his ex-wife's home, the documents show.
In recent years, he has made appearances on two reality television programs: "Mira Quien Baila" ("Look Who is Dancing") and "Es Macho Time."