This study examines employee knowledge of and satisfaction with a nonsmoking policy instituted at approximately 600 work sites of the New England Telephone company in 1986. A stratified random sample of employees was surveyed 20 months after the policy was implemented; 1120 (74.5%) returned surveys. Awareness of the rules about smoking in most areas was high, especially where smoking was totally banned. Respondents were highly satisfied with the policy, but half preferred additional restrictions on smoking. The policy was effective in reducing perceived environmental tobacco smoke exposure in work areas where smoking was banned but not in nonwork areas where smoking was allowed in designated areas. This study suggests that a highly restrictive nonsmoking policy--including a total ban on smoking--may be more easily and successfully implemented than are less restrictive policies.