Childhood abuse is an important public health problem; however, little is known about theeffects of abuse on the brain and neurobiological development. This article reviews the behavioraland biological consequences of childhood abuse and places them in a developmental context.Animal studies show that both positive and negative events early in life can influenceneurobiological development in unique ways. Early stressors such as maternal separation result inlasting effects on stress-responsive neurobiological systems, including thehypothalamic–pituitary–adrenal (HPA) axis and noradrenergic systems. Thesestudies also implicate a brain area involved in learning and memory, the hippocampus, in thelong-term consequences of early stress. Clinical studies of patients with a history of abuse alsoimplicate dysfunction in the HPA axis and the noradrenergic and hippocampal systems; however,there are multiple questions related to chronicity of stress, developmental epoch at the time of thestressor, presence of stress-related psychiatric disorders including posttraumatic stress disorderand depression, and psychological factors mediating the response to trauma that need to beaddressed in this field of research. Understanding the effects of abuse on the development of thebrain and neurobiology will nevertheless have important treatment and policy implications.