Medical students experience high levels of mental health problems, which can lead to poor academic performance, substance abuse and burnout. The current paper draws on social psychology to explore the factors underpinning wellbeing in medical students. From the literature it is evident that there is a strong association between group membership and wellbeing. There is also evidence, however, that when the norms of a group prescribe unhealthy behaviours, group members who identify strongly with the group are likely to engage in those behaviours. It was hypothesized that (a) there would be a positive relationship between identification and wellbeing in medical students, (b) perceptions of norms would be positively related to unhealthy behaviour which would be negatively related to wellbeing and (c) identification would be positively related to levels of norm-related unhealthy behaviour. Ninety-two Australian medical students completed measures of identification, endorsement of norms, own behaviour in relation to norms and three indicators of wellbeing. The results supported the first hypothesis and showed only partial support for the second, suggesting a primarily positive role of group processes in medical student wellbeing. The implications for interventions to improve wellbeing in medical schools and directions for future research are discussed.