"We are working on identifying how many children, women and men" were in the building, Guerrero state chief prosecutor Miguel Angel Godinez said, without giving details about the cause of death.
Acapulco has been beset by drug gang violence but it was not immediately clear whether the bodies were murder victims dumped by a gang, or whether the crematorium's operators left corpses there when the facility closed down.
"We can't say for now that there is an indication that organized crime participated in this, but we can't rule it out," Godinez told Radio Formula.
The prosecutor said authorities may carry out arrests but he declined to give more details.
Lime was scattered in the crematorium in an apparent bid to mask the smell.
The bodies were found late yesterday after neighbors complained about a foul smell coming from the crematorium, which was abandoned more than a year ago, a high-ranking state police official said on condition of anonymity.
The officer said the bodies were in an advanced state of decay.
Acapulco was once a favorite haunt of Hollywood stars, but the city has lost its flair over the years, while feuding drug gangs have turned it into one of Mexico's most violent places.
The aspiring teachers, all young men, vanished on September 26 in the city of Iguala, 210 kilometers north of Acapulco.
The Iguala case has sparked protests and turned into the biggest challenge of President Enrique Pena Nieto's two-year-old administration.
