OBJECTIVES: Smoking is a real public health problem, even in the medical profession. Our work was aimed at determining the prevalence of smoking in medical students in Casablanca and assess their attitude towards this problem. MATERIALS AND METHODS: A questionnaire enquiry was carried out during the 1994-1995 university year. All medical students in Casablanca (2,640) were invited to participate the questionnaire but only 1,321 (50%) responded. RESULTS: Prevalence of occasional or regular smoking was 13%. It increased progressively from first year students (13%) to sixth year students (21.5%) and was significantly higher in male students (25.7% versus 3.2% in females). 53.8% of the smokers were trying to stop. Ex-smokers accounted for 10.3% of the total 76.3% of the smokers hoped they would not be smoking within five years although level was 90% in ex-smokers. 90.9% of the students admitted that smoking is dangerous to health, (76% of the first year students and 94% of the fifth and sixth year students). The respiratory risks of smoking were well understood. 73.6% of students thought that convincing others not to smoke is a responsibility of doctors, but only 31.6% would do this in the absence of disease linked to smoking. CONCLUSIONS: There has been a net fall in the prevalence of smoking since 1982 (34% at that time compared with 13% in 1994) and the dangers of tobacco are better understood. Medical students understand the problem better. Courses about the pathology of tobacco smoking since 1983 have certainly contributed.