This chapter focuses on the evolution and characteristics of Rift Valley fever RVF policy-making in Kenya. Kenya has been the epicentre of several RVF outbreaks and has put into place specific policies to prepare for and address future outbreaks. RVF is a viral haemorrhagic fever affecting domestic livestock, wildlife and humans. Transmitted by mosquitoes, RVF is characterized by sporadic but significant epidemics that are associated with changes in land use and climate, specifically extensive flooding that precipitate pathogen and vector spread. RVF illustrates some of the challenges of disease prediction, forecasting and the operationalization of early warning systems in contexts of poverty, vulnerability and uncertainty. The chapter focuses on the ways in which knowledge claims in Kenya have become articulated and defended by different actors, including pastoralists, veterinarians, public health officials and senior policy-makers. Programmes of scientific work on RVF, funded by major donors, have made advances in virology, epidemiology, socio-economic assessments and the designing of surveillance systems.