An assessment of prevalence for systemic lupus erythematosus (SLE) has been attempted for the population of far north Queensland in Australia. This huge area has a majority Caucasian population living in a tropical environment. Roughly 10% of the population comprises people of Australian Aboriginal or Torres Strait Islander descent. The prevalence of disease was high (45.3 per 100000) overall and particularly so in the indigenous population (92.8 per 100000) where the disease appears to be more severe. The pattern of organ involvement and laboratory anomalies did not vary between the populations examined. Disease duration however was different, being longer by comparison in the Caucasian population due to many premature deaths in the indigenous groups. The reasons for such high prevalence figures and some problems encountered in practice are discussed.