A Metra spokesperson said a Union Pacific West Line train hit a man at the Kedzie station in Garfield Park around 6:30 p.m.
The man was transported to Mount Sinai Hospital in an unknown condition.
How the man ended up on the tracks was not immediately clear.
Trains in both directions were stalled as police investigated.
Metra said trains are on the move again with delays.
Further information was not immediately available.