Police said two men got into an argument inside a home at about 9:54 p.m. in the 13400-block of South Carondolet Avenue in the Hegewisch neighborhood.
One of them took out a handgun and shot the other man, police said.
Officers responded and found the victim on the front lawn and took him to the University of Chicago Medical Center in critical condition.
Police believed the suspect ran back into the home and a SWAT unit was called in. The suspect was not found after a search.
The scene was cleared and no one is in custody.