The fire broke out just before 6 a.m. on East 162nd Street.
The 86-year-old victim was pulled form the third floor of the building. He was unconscious in the street as rescuers worked on him, and he was rushed to Lincoln Hospital in critical condition.
Neighbors said the man was a hoarder and the apartment was cluttered.
Firefighters were able to quickly get the flames under control.
The cause of the fire is under investigation.