A number of researchers have found substantial sex, population and group differences in adiposity and fat-distribution patterns, but there is relatively little information on body fat distribution in Aboriginal groups, especially for the indigenous people of Australia. This study, the largest of its kind for Australian Aboriginal people, presents information on adiposity and fat distribution in 425 Yolngu, a group of Aboriginal people living in a number of communities representing a wide range of lifestyles, in northeast Arnhem Land, Australia. Using BMI standards developed for people of European descent, the majority of the individuals in this study were lean, and the incidence of obesity was considerably less than in other Australian groups, Aboriginal and non-Aboriginal. For the Yolngu in this study the relationship between ageing and adiposity is similar to that reported for tradition-orientated Aboriginal people, as well as for a number of other indigenous groups, viz., while the men maintain their weight into old age, the women, once they are past early adulthood, lose body fat with age. The results from the present study suggest that the age at which the Yolngu women start to gain, and subsequently lose, body fat is associated with differences in degree of acculturation. As has been found in other populations, age- and sex-related differences in body fat distribution occur, but no correlation was found between adiposity and fat distribution. The Aboriginal women and men, however, had a significantly more central distribution of subcutaneous fat than their non-Aboriginal counterparts. Our findings have implications for the health and demography of Aboriginal people in general, and the Yolngu in particular, as they continue the transition from hunting and foraging towards a more 'westernized' lifestyle.