Objective: Hepatitis B virus (HBV) infection remains an important cause of morbidity and mortality in Aboriginal and Torres Strait Islander people, who have high rates of infection compared with non-Indigenous Australians. We aimed to increase the evidence base around HBV in Aboriginal and Torres Strait Islander people through an analysis of routine clinical encounter data. Design: A cross-sectional study of de-identifi ed records from electronic patient systems over 5 years (8 January 2009 to 11 July 2013). Setting: Four Aboriginal community controlled health services. Participants: All patients attending for a clinical visit were included in the study. Hepatitis B testing records were included if at least one serological test for HBV was done. Main outcome measures: Percentage of clinical patients tested for hepatitis B, compliance with guidelines and serological status.Results: A total of 2959 people aged 15–54 years were screened for HBV, representing 17.2% of all people with a clinical visit in the study period. A total of 865 Aboriginal patients were tested concurrently for hepatitis B surface antigen (HBsAg), hepatitis B core antibody and hepatitis B surface antibody. Of those, 352 (40.7%) were susceptible to HBV infection (95% CI, 37.4%–43.9%) and 34 (3.9%) had either an acute or chronic infection indicated by a positive HBsAg result (95% CI, 2.6%–5.2%). In 329 women with antenatal screening, six (1.8%) returned a positive HBsAg result (95% CI, 0.37%–3.28%).Conclusion: A substantial proportion of patients tested were susceptible to HBV, with a high percentage potentially infectious compared with the general population. High levels of active infection and susceptibility to infection suggest many opportunities for transmission and indicate the potential benefi t of routine HBV testing and vaccination in this population.