The consequences of involuntary smoking are well documented. We conducted a survey among all employees of the University Hospital, Zurich, to assess their smoking habits and feelings about restrictions or a ban on smoking. In March 1995, a questionnaire was mailed to all 5230 hospital employees, 2620 (50.1%) completed forms were sent back. 76% of all staff are confronted with cigarette smoke during their worktime. 83% of these employees are distressed by tobacco smoke, and 43% feel that involuntary smoking affects their health. 19% of all employees are smokers. 19% of these are distressed by smokers at work themselves, whereas 13% feel that they are discriminated against by non-smokers. Restriction to designated smoking rooms (68%) or a ban on smoking (27%) would be supported by 95% of all employees. Even 89% of the smokers support smoking restrictions. These results show that there is a considerable demand for a smoke-free working environment among university hospital staff.