The purpose of this prospective study conducted from March to December 2000 in the Internal Medicine Department of the Sanou Souro University Hospital in Bobo-Dioulasso, Burkina Faso was to evaluate the epidemiological, clinical, biological and prognostic features of severe malaria in adult patients according to their HIV status. During the study period HIV testing was performed in 37 of the 72 adults with confirmed severe malaria. Findings were positive in 12 cases and negative in 25. The mean age of the 12 seropositive patients with severe malaria was 32.4 +/- 2.8 years and most (50%) had used self-prescribed antimalarial treatment. The most common reasons for seeking medical care were fever, headache and deterioration of general health. The main manifestations of severe malaria were coma (n=4), generalized seizure (n=4) and circulatory collapse (n=4). Six patients (50%) presented two severe manifestations. Mean parasitemia at the time of admission was 4066 parasites/microl for seropositive subjects versus 8563 parasites/microl for seronegative subjects. Outcome of malaria included 4 deaths and 8 recoveries in the seropositive group versus 2 deaths and 23 recoveries in the seronegative group. Comparison with the group of 25 seronegative patients presenting severe malaria demonstrated no significant difference in mean age (p=0.96), self-prescribed antimalarial treatment (p=0.50), parasitemia upon admission (p=0.28), or mortality (p=0.07). However co-infected patients were found to have a higher incidence of anemia (P=0.01) and never presented certain manifestations of severe malaria. Further studies of co-infection by HIV infection and malaria (especially severe malaria) is needed given the high human and economic impact of these two diseases in sub-Saharan Africa.