The fire broke out around 3:00 a.m. on the 7000 block of Frankford Avenue.
Crews arrived to flames showing on the first floor, which then spread to an apartment on the second floor.
A 60-year-old man was burned and suffered severe smoke inhalation. He was rushed to the hospital and is listed in critical condtion.
It took firefighters fifteen minutes to place the blaze under control.
Officials say the fire damaged a jewelry store on the first floor.
The Red Cross was called in to assist the displaced occupants.
So far, there is no word on what sparked the blaze.