The officer, who was off-duty at the time, responded to a call about criminal activity in the 100-block of West 80th Street.
The officer followed a vehicle matching the description to 47th and LaSalle. Police say the offender fired shots at the officer who then returned gunfire. The offender then reportedly ran from the scene.
The 43-year-old officer was transported to Northwestern Memorial Hospital with a graze wound to his side.