Peace in the Park After Dark is being held at Nat King Cole Park in the Chatham neighborhood.
"The city is still safe. And the message we're conveying is you shouldn't be afraid to utilize the parks and streets of Chicago," said Commander Eric Carter, Chicago Police Department.
Chicago Police Superintendent Gary McCarthy, other police officials and 100 youth and volunteers are taking part in the event.
Twenty people were shot within 24 hours in Chicago .