A total of 180 HIV-positive patients were assessed for seborrhoeic dermatitis (SD) and colonization with Malassezia species. Diseased skin of patients with seborrhoeic dermatitis were sampled selectively for Malassezia. In patients without SD, uninvolved skin was sampled. The prevalence of SD was 19%. Of the 34 SD patients, 16 were positive for Malassezia. Of the 146 patients without SD, only 27 were culture positive for Malassezia. Analysis of the largest HIV-positive patient population studied thus far yielded only a weak correlation between SD and Malassezia colonization.