Background: The main strategy for rolling back malaria in Africa is prompt, presumptive treatment of fever among those at risk. Most fevers in Africa are treated first with antipyretic or antimalarial drugs obtained from the retail sector. The objectives of the thesis were to understand retail provision of antimalarial drugs, drug use patterns and quality in four communities in Kenya to enable an exploration of impediments to effective antimalarial drug use in Kenya and how these might be redressed in the national antimalarial drug policy. Methods: The thesis used an eclectic mix of methods: from review of policy documents; key informant interviews; laboratory-based pharmaceutical analytical techniques; mathematical modeling of effectiveness; to structured questionnaires administered to households/retailers in four districts of Kenya. Results: The community survey revealed that less than 3% of children below five years accessed sulfadoxine/pyrimethamine (SP), the first-line drug. Adult and paediatric doses of SP and amodiaquine (AQ, second-line) in the retail retail sector were less than one US dollar; that of the new first-line drug, artemether-lumefantrine (ART-LUM) was eight US dollars. Less than a third of the retailers knew the correct dose of AQ for an adult and even less (2%) could state the correct dose for a child of 2 years. About 41% of SP and AQ products sampled from the retail sector were sub-standard. The modeled effectiveness of SP and AQ was found to be 51 and 45%, respectively, when drug quality, use, and adherence were taken into consideration; that of ART-LUM was approximately 85%. Conclusions: Effective drugs are not a panacea to therapy of malaria if they remain inaccessible to rural populations at risk in Kenya. The RBM targets on prompt, effective treatment of fevers are unlikely to be met without an increased investment in behaviour change initiatives and provision of effective and affordable therapeutics at all levels of the health service, including the retail sector.