The reporting of Aboriginal and Torres Strait Islander peoples on the NSW Admitted Patient Data Collection was ascertained using a stratified purposive sample of NSW public hospital patients in 2010. Information was collected by interviewing patients and compared with patient information obtained on admission. The study used the methods used in the national survey by the AIHW in 2007 and the study results were compared to the AIHW survey results. The level of correct reporting was 90.7% (95% CI 84.6–94.2). These results, while indicative, should be interpreted with caution as some people may not have identified themselves as Aboriginal or Torres Strait Islander either on hospital admission or in the survey, and non-random sampling can produce non-representative samples.