This multi-center, randomized, parallel-group, double-blind, double-dummy study compared the efficacy and safety of chlorproguanil-dapsone-artesunate (CDA) and chlorproguanil-dapsone (CPG-DDS) in the treatment of falciparum malaria in Africa (Burkina Faso, Ghana, Mali, Nigeria). Six hundred patients (>or= 1 year of age) received CDA 2.0/2.5/4.0 mg/kg, and 292 CPG-DDS 2.0/2.5 mg/kg, once daily for 3 days. Day 28 parasitologic cure rate (polymerase chain reaction [PCR]-corrected, per-protocol population) was 89.1% (416/467) for CDA, non-inferior but also superior to CPG-DDS, 83.0% (176/212) (treatment difference 6.1%; 95% confidence interval [CI] 0.3, 11.9). Glucose-6-phosphate dehydrogenase (G6PD) genotype was available for 844/892 (95%) patients. Occurrences of a composite hemoglobin safety endpoint (hemoglobin drop >or= 40 g/L or >or= 40% versus baseline, hemoglobin < 50 g/L, or blood transfusion) were CDA 13/44 (30%), CPG-DDS 7/24 (29%) in G6PD-deficient patients versus CDA 4/448 (< 1%), CPG-DDS 6/221 (3%) in G6PD-normal patients. No deaths occurred. CDA was more efficacious than CPG-DDS. However, the hemolytic potential in G6PD-deficient patients does not support further development of CDA.