The present study evaluates the evidence about the principal sources of fat in the Australian diet from the national per capita food supply data (apparent consumption; AC) and the national dietary survey of 6255 adults aged 25 to 64 years (NDSA). The AC and the NDSA data were converted to, and expressed on, an equivalent food basis to allow appropriate comparisons of foods consumed, and food sources of dietary fat. The AC figures showed that the principal sources of fat nationally were meat, edible fats, fat spreads and oils, and milk and milk products. As an estimate of adult food consumption the AC underestimated beef and veal, lamb, total meat, and poultry consumption by 41, 10, 29 and 13% respectively, and overestimated offal, milk and milk products, and fats and oils by 15, 61, 20, and 29% respectively. The AC data rated fat spreads and cooking fats as providing more of the fat in the adult diet than did the NDSA, both in terms of total fat and fat as a percentage of energy. Conversely, on this same basis, the AC underrated meats as sources of fat in the adult diet. Other foods were of similar importance as sources of dietary fat in both sets of data. The AC markedly underestimated adult fat intake at 32% of energy compared with the NDSA result of 37%. These results have implications for epidemiological research and for the development of food and nutrition policy and programmes in Australia and similar countries.