The Cessna 210N plane crashed into a two-story building and it was unclear whether the victims were in the plane or on the ground. It had taken off from the small Campo do Marte airfield.
The extent of the injuries was not clear and there was no immediate word on the cause of the crash. Sao Paulo's metropolitan area saw scattered showers all afternoon on Friday.
Video taken by bystanders just after the crash and aired on Globo showed flames engulfing two buildings and vehicles parked along a street. The fire was under control within half an hour.
(With inputs from agencies.)