Post-traumatic Stress Disorder (PTSD) is a syndrome defined by the intrusive re-experiencing of a trauma, avoidance of traumatic reminders, and persistent physiological arousal. PTSD is associated with high levels of comorbidity and may increase the risk for additional disorders over time. While controversies remain regarding the applicability of the PTSD criteria to very young children, it has proved to be a useful framework for guiding assessment and treatment research with older children and adolescents. This article presents an overview of the literature on the clinical characteristics, assessment, and treatment of PTSD in children and adolescents.