Powdery mildew pathogens are among the most important cereal disease-causing organisms, and can result in significant losses in yield and reductions in grain quality. They pose a significant challenge for barley and wheat agricultural production systems. This chapter aims to provide an overview of current knowledge on wheat and barley resistance to powdery mildew. First, we introduce basic biological concepts on disease epidemiology and management strategies which target mildew. We then present emerging trends and technologies used in mildew resistance breeding and research and discuss how these could be combined into effective disease management strategies in the near future. Finally, we propose additional directions for achieving durable resistance based on deep understanding of the basic molecular mechanisms of cereal-mildew interactions.