The study of risk in individual development played an instrumental role in the origin of contemporary developmental psychopathology and the emergence of resilience studies. This chapter provides an overview of progress and ongoing issues encountered in the developmental study of risk and adversity. It addresses different approaches for examining effects of risk and adversity on development. The chapter first discusses risk factors and cumulative risk indices, emphasizing environmental and sociodemographic status variables. It then focuses on stressful life events and efforts to measure ongoing adversity exposure. The chapter also examines major issues in defining, measuring, and investigating developmental risk and adversity, while highlighting important new research directions. Better standardization of risk and adversity measures allow researchers to investigate how the effects of specific levels of risk and adversity and processes underlying those effects vary across different contexts and population.