The report found that Garner, 43, was killed by being placed in a chokehold and compression on his chest. The cause of death was listed as homicide.
Garner's death on July 17 is under investigation by the Staten Island District Attorney, the FBI is also reviewing the case.
A videotape showed Garner, who was allegedly selling cigarettes illegally on the street in Staten Island, arguing with police officers. As the argument heated up, an officer placed an arm around Garner's neck and pulled him to the ground.
"I can't breathe," Garner can be heard saying.
Garner was overweight and suffered from diabetes and other conditions associated with obesity. The medical examiner found his health problems contributed to his death but did not cause it.
The New York Police Department has banned officers from using the chokehold for 20 years. Mayor Bill de Blasio, in a statement Friday, pledged that he and Police Commissioner William Bratton would make sure that Garner's death and department training are reviewed.
"We all have a responsibility to work together to heal the wounds from decades of mistrust and create a culture where the Police Department and the communities they protect respect each other -- and that's a responsibility that Commissioner Bratton and I take very seriously," the mayor said. "I've said that we would make change, and we will."