Sudre P (Malaria Branch, Division of Parasitic Diseases, National Center for infectious Diseases, Centers for Disease Control, Public Health Service, US Department of Health and Human Services, Atlanta, GA 30333, USA), Breman J G, McFarland D and Koplan J P. Treatment of chloroquine-resistant malaria in African children: A cost-effectiveness analysis. International Journal of Epidemiology 1992; 21: 146–154. Because chloroquine (Cq)-resistant Plasmodium falciparum (CRPF) has now spread throughout most of Africa, the efficacy and practicability of other drugs such as amodiaquine (Aq), and pyrimethamine-suffadoxine (PS), for the treatment of fever needs to be assessed. We used a decision-analysis model to compare the cost and effectiveness of Cq. Aq, and PS. The variables considered were the probability of P. falciparum infection, drug compliance, minor and lethal side effects of the drug, the level of drug resistance in the community, and case-fatality rates associated with treatment. The measures of effectiveness were the number of malaria-related fever episodes cured parasitologically with each treatment and the number of malaria deaths prevented in children 6–59 months old. Cost-effectiveness comparisons were made for cases cured and deaths prevented. For treating 100000 febnle episodes, Cq, PS, and Aq cost US$1812, US$2622, and US$3044, respectively. Cost of the drug, compliance, and the level of CRPF had the greatest effect on the cost-effectiveness ratio. The prevalence of high-level drug resistance (RIII) was the most important deter minant of the cost-effectiveness. In a scenario with high-level CRPF, treatment with Cq costs US$0.47 to cure one patient and US$2.26 to prevent one death compared with US$0.05 and US$1.52 for treatment with PS. When the prevalence of RIII-level CRPF is greater than 14–31% (depending on the level of compliance), the most cost-effective treatment is PS, despite its 45% greater cost. Decision analysis models will be useful for malaria control planners as strategies are reconsidered in the 1990s.