To present Australian normative data on the ten-item Kessler Psychological Distress Scale (K10). Analysis of cross-sectional data from the 2007 Australian National Survey of Mental Health and Wellbeing, a nationally representative household survey of 8841 adults. Mean K10 scores and K10 scores at selected percentiles of the K10 score distribution are presented by sex, age, the presence of mental disorders and the presence of physical conditions. Stratum-specific likelihood ratios were computed to help clinicians and researchers calculate predicted probabilities of mental disorder given scores on the K10. Scores on the K10 were generally higher in women compared to men, in people with a mental disorder compared to without a mental disorder and in people with affective disorders compared to people with substance use disorders. The SSLRs were informative in ruling in a diagnosis of mental disorder, particularly at the high or very high end of the psychological distress spectrum. These data may be helpful for clinicians and researchers alike in understanding the likelihood of mental disorder in a given individual or sample.