This paper investigates how rural farm households adapt to the risk of disease. In the context of malaria, adaptation brings to mind mosquito nets, sprays and coils. However, adaptation may bemore subtle. For instance, households living in malaria-endemic regions may alter their crop choice to reduce their exposure to disease and the associated likelihood of crop failure. Thus the risk of malaria places a significant economic burden on households even if they do not actually suffer an episode of malaria. In this paper, we examine these issues using a unique dataset from Viet Nam where malaria declined dramatically during the 1990s due to a nationwide malaria control program. The main finding of this paper is that malaria risk has a significant and negative impact on agricultural production.