We have earlier obtained good results in falciparum malaria by treating children with low doses of quinine for 7 days in Guinea-Bissau. In order to further simplify treatment, we compared outcome in 100 children with falciparum malaria treated in 1999/2000 for 7 days with 15 mg quinine salt/kg/dose twice daily (group I), 100 children treated with 7.5 mg quinine salt/kg/dose twice daily (group II), and 100 children treated with one single daily dose of 15 mg/kg. One day 28, parasites had reappeared in 12%, 15%, and 9%, respectively. These results are similar to what has been found after previous successful treatment regimens. Apart from a higher incidence of vomiting during the first 24 h of treatment in the groups treated with 15 mg/kg/dose no significant differences in symptoms or side-effects were found between the groups. In patients suffering from uncomplicated malaria, treatment with quinine can be simplified to one single dose of 15 mg/kg bodyweight whenever logistics make 2 daily doses less feasible.