This open-label multicenter pharmacokinetics study was carried out at three public dispensaries for children (Colsama, Ouezzin-Ville, and Sarfalao) in Bobo-Dioulasso, Burkina Faso, from August to December of 2007 (see Supplementary Materials and Methods online). This is an area with a high rate of seasonal malaria transmission from August to October. This study was nested into a larger study of the efficacy and safety of dihydroartemisinin-piperaquine in children, to be reported in full elsewhere (unpublished data). The study was approved by the Committee on Human Research of the University of California, San Francisco, and the Comite d’Ethique Institutionnel du Centre Muraz, Bobo-Dioulasso. The parents or guardians of all the participants gave their informed consent in writing prior to study entry. The trial was registered with Current Controlled Trials (http://www.controlled-trials.com/ISRCTN59761234).