The 84-year-old Berry seemed to have trouble keeping his guitar in tune and at times sat down to play at a keyboard before leaving the stage about an hour into his performance, the Chicago Tribune reported.
After being checked by the emergency crew Berry returned to the stage and thanked those remaining in the audience, then left without performing again.
Chicago Fire Department Fire Media Affairs spokesman Chief Joe Roccasalva said Berry signed a release saying he was alright and wasn't taken to a hospital.
Berry left the scene in a limousine.
The Rock and Roll Hall of Fame guitarist, singer and songwriter is considered one of the pioneers of rock and roll music. Among his best-known songs are "Johnny B. Goode," "Rock and Roll Music," "Roll Over Beethoven," and "Maybellene."