OBJECTIVES:To determine the proportion of Aboriginal Controlled Community Health Service (ACCHS) patients tested according to three national diabetes testing guidelines; to investigate whether specific patient characteristics were associated with being tested. DESIGN, SETTING AND PARTICIPANTS:Cross-sectional study of 20 978 adult Indigenous Australians not diagnosed with diabetes attending 18 ACCHSs across Australia. De-identified electronic whole service data for July 2010 - June 2013 were analysed. MAIN OUTCOMES MEASURES:Proportions of patients appropriately screened for diabetes according to three national guidelines for Indigenous Australians: National Health and Medical Research Council (at least once every 3 years for those aged 35 years or more); Royal Australian College of General Practitioners and Diabetes Australia (at least once every 3 years for those aged 18 years or more); National Aboriginal Community Controlled Health Organisation (annual testing of those aged 18 years or more at high risk of diabetes). RESULTS:74% (95% CI, 74-75%) of Indigenous adults and 77% (95% CI, 76-78%) of 10 760 patients aged 35 or more had been tested for diabetes at least once in the past 3 years. The proportions of patients tested varied between services (range: all adults, 16-90%; people aged 35 years or more, 23-92%). 18% (95% CI, 18-19%) of patients aged 18 or more were tested for diabetes annually (range, 0.1-43%). Patients were less likely to be tested if they were under 50 years of age, were transient rather than current patients of the ACCHS, or attended the service less frequently. CONCLUSIONS:Some services achieved high rates of 3-yearly testing of Indigenous Australians for diabetes, but recommended rates of annual testing were rarely attained. ACCHSs may need assistance to achieve desirable levels of testing.