Objective To investigate on-campus mental health service utilisation by Australian university students. Method Retrospective analysis of clinical data from two on-campus health services (general practice and psychology and counselling service). Descriptive statistics include total consults, demographic factors, diagnoses, presenting concerns and rates of suicidal ideation. Results Mental health conditions account for the largest proportion of ongoing illness in on-campus health service users, representing 46% of all ongoing health conditions. Depression and anxiety were the most common diagnoses, and stress, anxiety and low mood were the most common presenting concerns. Females utilise mental health services more frequently than males, accounting for 65.3% and 60.1% of patients for the respective services. International students present for specific mental health consults less frequently than domestic students. Rates of suicidal ideation at presentation were high (37%). Conclusions This retrospective analysis provides important information regarding the proportion and distribution of mental health conditions and service utilisation amongst Australian university students. There is clear scope for increased access to specialist care, renewed efforts to decrease stigma and increase rates of presentation (particularly amongst international students and males), greater support for general practitioners and more rigorous routine data collection and reporting, both within and across universities nationally.