To determine, using face-to-face diagnostic interviews, the prevalence of common mental disorders (CMD) in a cohort of adult Indigenous Australians, the cultural acceptability of the interviews, the rates of comorbid CMD and concordance with psychiatrists’ diagnoses. Cross-sectional study July 2014-November 2016. Psychologists conducted Structured Clinical Interviews for Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision Axis I Disorders (SCID-I) (n=544). Psychiatrists interviewed a subsample (n=78). Four Aboriginal Medical Services and the general community located in urban, regional and remote areas of Southern Queensland and two Aboriginal Reserves located in New South Wales.