It happened around 8:30 Friday evening on the 200 block of West Wyoming Avenue.
Police said a witness reported that someone knocked on the door and two masked men armed with a revolver demanded money and then shot the victim.
Officers found a 56-year-old man in the living room with a gunshot wound to the head. Police said he was unresponsive and was taken to Einstein Medical Center "in very critical condition."
Police said the men continued to search the house before fleeing; it's unknown whether anything was taken.
The suspects remain at large.