This cross sectional study took place with a self administered questionnaire between June and September 1999 and involved 1,388 subjects of whom 62.4% were men and 37.6% women. The total prevalence of smoking was 14.9%, ranging from 12.5% in paramedical staff to 15.5% in manual workers, 16.2% in doctors, 17.1% in laboratory staff, and 22.2% in administrators. The prevalence was 35.9% among men as against 2.2% among women. The study of smokers showed that 51.5% had started before the age of 21. The most common motive for starting smoking was "pleasure". Among the 45.5% who smoked at the workplace 60.5% felt concerned about it. Evaluation of the degree of nicotine dependence using the Fagerstrom score found high dependence in 21.3% of subjects. Only 24.5% of doctors warned patients against smoking in the absence of smoking related diseases or symptoms. In more than 75% of cases doctors advised against smoking in the workplace and in the home. 66.8% of staff were aware of the anti-smoking law but the legislative measures were poorly understood. Only 9% of those interviewed had taken part in an anti-smoking campaign. In conclusion, the prevalence of smoking in the hospitals of Casablanca has definitely diminished in the past 10 years but it remains relatively high in men. Hospital staff should be more involved in the fight against smoking.