To identify the incidence and distribution of public hospital admissions in South Australia that could potentially be prevented with appropriate use of primary care services, analysis was completed of all public hospital separations from July 2006 to June 2008 in SA. This included those classified as potentially preventable using the Australian Institute of Health and Welfare criteria for selected potentially preventable hospitalisations (SPPH), by events and by individual, with statistical local area geocoding and allocation of relative socioeconomic disadvantage quintile. A total of 744 723 public hospital separations were recorded, of which 79 424 (10.7%) were classified as potentially preventable. Of these, 59% were for chronic conditions, and 29% were derived from the bottom socioeconomic status (SES) quintile. Individuals in the lowest SES quintile were 2.5 times more likely to be admitted for a potentially preventable condition than those from the top SES quintile. Older individuals, males, those in the most disadvantaged quintiles, non-metropolitan areas and Indigenous people were more likely to have more than one preventable admission.