Over the past decade there has been a massive scale-up of antimalarial interventions including insecticide-treated nets (ITNs), artemisinin-combination treatments (ACTs), and rapid-diagnostic tests (RDTs), and in selected areas, indoor residual spraying. This scale-up is beginning to have a significant impact on the burden of malaria in many areas worldwide. In the most recent World Malaria Report, the World Health Organization (WHO) estimated that in 2010 there was an 8% decrease in the number of cases (compared with 2005) and a 21% decrease in the number of deaths (compared with 2000). Against this backdrop of rapidly changing epidemiology, good monitoring, surveillance, and robust methods for estimating malaria burden are essential for documentation of program success as well as the identification of problem areas.