A woman's body was found just before 11 a.m. Saturday in the 7600 block of Este Avenue.
Philadelphia police say construction workers found the body in the rubble of the demolished building.
The building, which was divided into apartments, caught fire around 2:30 a.m. Thursday.
The flames broke out in the lower level of the building and spread from there.
Firefighters hosed down the top level as the fire shot through the roof.
There was no immediate word as to how the woman died.
There had been no word of anyone injured or missing after Thursday's fire.