The ordinance was passed in response to a U.S. Supreme Court decision that made the city's handgun ban unenforceable.
The ban went into effect Monday.
It prohibits gun owners from stepping outside their homes with a handgun and bans gun shops in Chicago.
At least two lawsuits have been filed challenging the ordinance.
Mayor Daley says it is designed to protect the city and its citizens.
Gun rights supporters argue the city's new gun control ordinance is too strict... And its making it difficult for law abiding citizens to own guns.