These practice parameters review the current state of knowledge about posttraumatic stress disorder (PTSD) in children and adolescents. The parameters were written to aid clinicians in the assessment and treatment of children and adolescents with PTSD symptoms. A literature search and extensive review were conducted in order to evaluate the existing empirical and clinical information in this regard. Expert consultation was also solicited. The main findings of this process were that a wide variety of stressors can lead to the development of PTSD symptoms in this population; that the specific PTSD symptoms manifested may vary according to the developmental stage of the child and the nature of the stressor, and for this reason, the diagnostic criteria for PTSD in adults may not adequately describe this disorder in children and adolescents; that several factors seem to mediate the development of childhood PTSD following a severe stressor; and that most of the therapeutic interventions recommended for children with PTSD are trauma-focused and include some degree of direct discussion of the trauma. Controversies and unresolved issues regarding PTSD in children are also addressed.