It's already banned in California offices, restaurants and on miles of beaches, but today the rural city of Calabasas goes a step further.
The town has enacted the first law in the United States banning smoking on streets, at bus stops and in all other public places where people can be exposed to second-hand smoke.
"People have a right to breathe clean air. It is time to stand up to the challenges, the critics and to tobacco interests," Calabasas mayor Barry Groveman told a news conference.
The law was passed unanimously last month by the city council in the affluent canyon community of 21,000 people northwest of Los Angeles.
The ban means an end to smokers huddling outside offices, lighting up on outdoor restaurant patios, or puffing on their apartment balconies if they are near common areas such as pools or laundry rooms. From now on, smokers will be asked to go to designated areas, or will be handed small cards outlining the new law. Persistent offenders risk fines of up to $500.
"We don't anticipate any problems with compliance. We are hearing nothing but positive comments," said Mr Groveman.
Supported by the American Cancer Society, Heart Association and Lung Association, the Calabasas ordinance follows a landmark January decision by the California Air Resources Board to classify second-hand tobacco smoke as a "toxic air contaminant".
Health officials say a series of California laws that banned smoking in restaurants, bars and the workplace are not enough to protect people from the harmful effects of second-hand smoke.
"Having a smoking area in a restaurant is like having a peeing section in a swimming pool," said Dr Thomas Pfeffer of the American Heart Association in Los Angeles.