Aims of the study were to compare medical students (MS) to non-MS with respect to their knowledge of smoking and to investigate the effect of a short educational intervention on MS knowledge. MS (n = 962) and students of architecture and law (n = 229) were asked to complete a 60-item questionnaire addressing knowledge of smoking epidemiology and health effects ("Score 1"), and effectiveness of cessation treatments ("Score 2"). Upon completion of questionnaire, fourth year MS received a lecture on tobacco dependence. These students were asked to complete the same questionnaire one and two years later. Mean values for Score 1 were 48.9 ± 11.5% in MS and 40.5 ± 11.4% in non-MS (P < 0.001; d = 0.69). Respective values for Score 2 were 48.1 ± 10.8% and 42.6 ± 10.6% (P < 0.001; d = 0.50). Fifth year students who had attended the lecture in year 4 scored higher than students who had not attended the lecture. Significant differences were noted one but not two years after the educational intervention. In conclusion, MS know slightly more about smoking-related diseases and methods to achieve cessation than nonmedical students; a short educational intervention was associated with better knowledge one year later, but the effect was moderate and short-lived.