Police said the shooting happened in the Garfield Park neighborhood's 3300-block of West Maypole Avenue just before 12:45 a.m.
A group of people was standing on the street when unknown offenders exchanged gunfire, police said.
A 33-year-old man, shot in his lower back, was transported to Stroger Hospital in critical condition.
A 30-year-old man, also shot in his back, was dropped off at Mount Sinai Hospital in critical condition.
Another man, 32, was dropped off at the same hospital with a gunshot wound to his calf. He was in fair condition.
No one is in custody and Area Four detectives are investigating.
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