SMC involves monthly administration of an antimalarial drug or drug combination in a full therapeutic course to children on three of four occasions during the period of highest risk of malaria infection. Studies undertaken in several countries in West Africa, including Burkina Faso and Mali, have shown that SMC with sulphadoxine/pyrimethamine (SP) and amodiaquine (AQ) is highly effective in areas where the transmission of malaria is markedly seasonal, reducing the incidence of severe and uncomplicated malaria by up to 80%. SMC with a combination of SP and AQ is safe, with no serious drug related adverse event being reported after administration of over 800,000 courses in Senegal. Recent studies have defined the areas where SMC would be an appropriate intervention based on the seasonality and incidence of malaria. These include most of the Sahel and sub-Sahel, population approximately 200 million, and possibly other areas in southern and eastern Africa. A Technical Expert Group of the WHO reviewed all the available evidence on the efficacy and safety of SMC in May 2011 and recommended SMC with SP+AQ in areas of the Sahel and sub-Sahel with highly seasonal transmission. This recommendation was endorsed by the WHO Malaria Policy Advisory Committee (MPAC) in February 2012. Most countries in the Sahel and sub-Sahel region have incorporated SMC, along with other malaria control interventions in their strategic malaria control plan and the implementation of SMC at scale is in progress in many countries in this region through the UNITAID supported SMC ACCESS programme and the support of other major donor organisations. Preliminary evaluation suggests that SMC is providing about 50% protection against clinical malaria when delivered through a national programme (http://www.malariaconsortium.org/pages/access-smc.htm).