AIM: The aim of this study was to estimate the prevalence of illicit drug use among medical students in Northern Greece, to identify the motivations for cannabis use and also to investigate the possible associations with smoking and alcohol misuse.METHODS: A sample of undergraduate students completed an anonymous, self-administered, web-based survey assessing lifetime and past-year illicit substance use. To further evaluate the motivation to use, the responders were classified into three subtypes (self-medication, recreational, and mixed). The CAGE questionnaire and a question assessing binge drinking were also used. Illicit substance use was correlated with age, gender, study year, CAGE and binge drinking.RESULTS: Five hundred and ninety-one undergraduate medical students completed the survey. The lifetime prevalence of illicit drug use was 24.7 %, while the most used drug was cannabis (22.2 %). The past-month prevalence of cannabis use was 8.1 %. Experimentation was the predominant reported motivation for its use, and the recreational subtype was the most prevalent. Binge drinking behavior was reported by 22.7 % of the sample, and the CAGE screening test was positive for 6.4 % of the students. Most students (80.4 %) characterized themselves as non-smokers. In the multivariate analysis, lifetime use of illicit drugs was significantly correlated with smoking and binge drinking. No associations were found with gender, age, study year or CAGE.CONCLUSION: Smoking and binge drinking were found to be risk factors for illicit drug use, whereas no association was found with gender, age, study year and CAGE. HIPPOKRATIA 2017, 21(1): 13-18.