This Special Issue of Development and Psychopathology is devoted to the psychological and biological consequences of stress across the developmental course. Contributions in this Special Issue address topics that are central to elucidating the impact that stress exerts on developmental outcomes. These issues are investigated through examining a diverse array of populations, including rodent and nonhuman primate samples, as well as cohorts of maltreated children and adolescents with and without posttraumatic stress disorder (PTSD), children who were adopted from Romanian orphanages at differing points during infancy, aging Holocaust survivors and their offspring, children with depressive disorder, adolescents with schizotypal personality disorder, and adults with bipolar and unipolar mood disorders.