Youths who have been maltreated often experience symptoms of posttraumatic stress disorder (PTSD), and this special population has received increased attention from researchers. Pathways toward maladaptive effects of maltreatment and PTSD are remarkably similar and reflect specific biological diatheses and psychological vulnerabilities that produce wide-ranging self-regulation deficits. Developmental models of effects of maltreatment and of PTSD are thus increasingly intertwined and have begun to inform specialized assessment and treatment strategies for this population. This review covers key aspects of posttraumatic stress disorder in maltreated youth, including epidemiology, symptomatology, outcome, and risk factors as well as assessment and treatment strategies and challenges for these youths.