The health hazards due to exposure to environmental tobacco smoke (ETS) are increasingly established. ETS contains thousands of chemicals including 43 known carcinogens. Known health effects of ETS exposure are lung cancer in nonsmokers, childhood disorders such as bronchitis, and perhaps, heart disease. Workplace exposure to ETS is widespread and is influenced strongly by the type of smoking policy in the workplace. To decrease ETS exposure, efforts to restrict public smoking have proliferated over the past decade. These restrictions have emanated from government as well as voluntary measures by various private industries. Bans on public smoking are effective in reducing nonsmokers' exposure to ETS. Workplace smoking bans also influence the intensity of smoking among employees and may increase quit smoking rates. In addition to the health benefits from smoke-free workplaces, there are likely cost savings to employers who implement such policies.