Using data from the Demographic and Health Survey, this article analyses the relationship between HIV status and the socio-economic and demographic characteristics of adults in Lesotho, Malawi, Swaziland and Zimbabwe. It constructs the risk profile of the average adult, computes the values of age, education and wealth where the estimated probability of infection assumes its highest value, and determines the percentage of adults for whom these three factors are positively correlated with that probability. It finds that in all four countries: (i) the probability of being HIV-positive is higher for women than for men; (ii) the likelihood of infection is higher for urban than for rural residents; and (iii) there is an inverted-U relationship between age and HIV status. Also that, unlike gender, rural/urban residence and age, the relationship between the probability of infection and wealth, education and marital status varies by country. The results provide support for country-specific and more targeted HIV policies and programmes.