At about 6:14 p.m. a witness called West Chicago police saying there were two men injured inside a car in the 700-block of W. Forest Avenue.
Police found two men with gunshot wounds. Both were pronounced dead at the scene.
A third man was taken to an area hospital with a non-life-threatening gunshot wound.
Police said they are questioning at least one other person believed to be a suspect.
Anyone with information is asked to call police at (630) 293-2222.
Police said they believe it is an isolated event.