The aims of this study were a) to investigate patterns of alcohol, smoking and illicit drug use and b) evaluate the relationship between substance abuse and personality factors in a cohort of 267 first year medical students. 12.3 % (men) and 11.8% (female) medical students reported to be drinking above the “low risk” level of alcohol. Illicit drug use was present amongst the students surveyed, with 12.4% having experimented with cannabis at some stage during their life. A significant proportion of the students (44.1%) suffered from anxiety. There are personality characteristics like extraversion and openness that influence the drug taking and drinking habits of students, suggesting that such individuals may still pursue these habits although they know these are not healthy habits. Considering these, it may be prudent to consider the promotion of harm reduction and safer use of drugs and alcohol in medical students.