Nonsmoking policies are being implemented increasingly in worksites across the country. This cross-sectional study examined attitudes toward worksite nonsmoking policies and worksite norms about smoking and cessation. Data were collected by telephone interview from 711 smokers and recent ex-smokers employed in seven worksites in Bloomington, Minnesota, in 1986. The findings indicated widespread support for nonsmoking policies even among smokers. Support for nonsmoking policies was especially high among respondents interested in quitting smoking, those concerned about the health effects of smoking, those reporting high coworker support for prior cessation attempts, and those working with a high proportion of nonsmokers. Support for nonsmoking policies was also correlated with smoking cessation in the 18 months prior to the survey. The clustering of these social norms is indicative of a worksite "culture" that may either support nonsmoking or inhibit cessation.