A comparison of congenital malformations in Aboriginal and non-Aboriginal children in Western Australia has been made by means of data from the WA Congenital Malformations Registry, for births from 1980 to 1987 inclusive. Although the birth prevalence of all malformations was 3.5% for both Aboriginal and non-Aboriginal infants, significant differences were found in the birth prevalence of some individual malformations. Nervous-system and cardiovascular defects, and cleft lip and palate were significantly more prevalent in Aborigines, and pyloric stenosis and urogenital defects were significantly less prevalent. While some of the observed differences may have been a result of biases in ascertainment, others are likely to represent true differences. A discussion of Aboriginal beliefs concerning conception and birth is included, in order that the quantitative findings from the study might be considered in an appropriate cultural setting.