This report makes a case for the importance of antimalarial drug monitoring as an integral part of disease surveillance programmes in developing countries. Antimalarials are some of the most commonly counterfeited drugs — the high prevalence of malaria translates to a large consumer market in the developing world. The problem is serious in South-East Asia but is expected to become significant in African countries too. The report suggests that scientists ensure drugs are genuine and of a good quality before conducting efficacy or resistance studies in areas where counterfeits circulate widely.