A random sample of employees was surveyed 20 months after a non-smoking policy was implemented at the New England Telephone Company in 1986. Overall, 21 percent of respondents who were smoking at the time they heard about the policy had quit smoking; 42 percent of quitters said they stopped smoking because of the policy. Cessation was highest among those who reported less smoke in their work area, but was not related to participation in cessation programs. This study suggests that worksite nonsmoking policies may have favorable effects on smoking cessation.