OBJECTIVE:To obtain prevalence estimates of clinical features of obstructive sleep apnoea (OSA) and identify the dimensions of the public health problem requiring further investigation for an Australian population. METHODS:The South Australian Health Omnibus Survey is an annual representative population survey of South Australians aged≥15 years, conducted via interviewer-administered questionnaire. In 2009, 3007 participants were asked the STOP-BANG instrument measure of obstructive sleep apnoea risk, which includes symptoms of loud snoring, frequent tiredness during daytime, observed apnoea, and high blood pressure (STOP), and measured body mass index, age, neck circumference and gender (BANG). Three or more positive response categorises a person at high risk for OSA. RESULTS:Snoring was reported by 49.7% of adults. Tiredness after sleep more than 3 - 4 times per week was reported by 24.8%, and during wake-time by 27.7% of adults, with 8.8% reporting having fallen asleep while driving. Over half of the surveyed men (57.1%, n=566) and 19.3% (n=269) of the women were classified at high-risk of OSA with the STOP-BANG measure. In multivariable models, high risk was associated with less education, lower income, and residence in a regional rather than metropolitan area. CONCLUSION:The high prevalence of adults at risk for OSA suggests that the capacity currently available within the healthcare system to investigate and diagnose OSA is likely to be inadequate, particularly outside urban areas. This highlights an important public health problem that requires further detailed study and trials of new models of care.