Although artemisinin and its derivatives are widely used for the treatment of malaria, they also have antischistosomal activity. In a small study in eastern Sudan, the effects of the treatment of uncomplicated, Plasmodium falciparum malaria with artesunate-sulfamethoxypyrazine-pyrimethamine (AS-SMP) and artemether-lumefantrine (AT-LU) on co-infections with Schistosoma mansoni were therefore investigated. Faecal samples from 14 of the 306 patients screened on presentation, at the start of a clinical trial of antimalarial treatment, were found to contain Schistosoma mansoni eggs. For the treatment of their malaria, the 14 egg-positive cases, who were aged 6-40 years (mean = 13.7 years), were each subsequently treated with three tablets of a fixed combination of AS-SMP, with a 12-h (six patients) or 24-h interval (five patients) between each tablet, or with six doses of AT-LU given over 3 days. When checked 28 and 29 days after the initiation of treatment, all 14 patients were found stool-negative for schistosome eggs. These results indicate that AS-SMP and AT-LU are currently very effective treatments not only for uncomplicated, P. falciparum malaria but also for S. mansoni infections.