OBJECTIVES: The purpose of this study was to evaluate the affordability of Antimalarial Drugs using real world data from private pharmacies, missionary and government hospitals in Benin city, Nigeria. METHODS: The mean ± SD of prices that patients prescribed Antimalarials in Benin city pay for a standard regimen when they have malaria was collected from private pharmacies,missionary and government hospitals. Minimum wage was obtained directly from the least paid unskilled government workers.The data was used to develop a stochastic monte carlo model that calculates affordability of an Antimalarial drug (in days' wages). Two markov models that use 2007 data to project prices of antimalarial drugs and monthly minimum wages into the future using inflation rates, prices of antimalarials, percentage increase in wages and a fixed discount rate of 5% were also built.Results of the markov models serve as inputs for the monte carlo simulations so that affordability can thus be projected into the future for the next 10 years. All three models reported 1000 observations averaged over 10 repeated simulations. RESULTS: Branded Antimalarial drugs were less affordable compared to the lowest priced generic versions (p<0.0001). Branded chloroquine tablets were 290% more expensive than the unbranded and the least paid unskilled government worker would need to spend about 20 days' wages to treat malaria with artemether 80mg/ml injection. Antimalarials from missionary and government hospitals were not necessarily more affordable than those bought in private pharmacies.Peadiatric dihydroartemisinin 160mg/80ml may become 182% less affordable in 2012 and 226% less affordable by 2017 (p<0.0001). All Antimalarials studied exhibited a similar trend. Sensitivity analyses showed that these findings were robust. CONCLUSION: Unless deliberate public health policies address the affordability of antimalarials; it is unlikely that there will be any reduction in malaria morbidity and mortality in the poor.