Drug resistance is a major problem affecting progress on malaria control, while many current programmes are seeking to introduce impregnated bednets to reduce transmission and hence child mortality and morbidity. David Molyneux, Katherine Floyd, Guy Barnish and Eric Fèvre propose that more consideration should be given to the interaction between transmission control and the development of drug resistance, and that vector control as a means of reducing disease transmission is involved in reducing the rate of development, and the level, of resistance. Therefore, investment in vector control can have important benefits in reducing the future expenditure on drugs (as well as other costs, such as hospitalization, management of resistant cases and severe disease, drug development and household expenditure on malaria chemotherapy). Modelling the many parameters that impact on this complex relationship will better inform policy makers.