The authors investigated the impact of a complete smoking ban on 349 employees of a cancer treatment center. A questionnaire administered approximately 4 months after the ban was initiated queried smokers on the impact of the ban on their smoking habits, their experience of withdrawal symptoms during the workday, and changes in work habits. A separate questionnaire asked nonsmokers about changes in the work environment. Results showed that few smokers quit while a majority decreased their consumption. Withdrawal symptoms were a problem in less than half the smokers, but those reporting signs of physical dependency on nicotine tended to smoke more before and after work and reported negative changes in work performance. Nonsmokers in general reported positive effects on the work environment.