Children are exposed to a variety of traumatic experiences, and each child is unique in his or her response to that trauma. The most common psychiatric disorder that develops after exposure to trauma is posttraumatic stress disorder (PTSD). This article will help pediatric nurse practitioners understand PTSD in terms of diagnosis, epidemiology, risk factors, comorbidity, and treatment. DSM-IV diagnostic criteria will be discussed, along with modifications to consider when evaluating very young children for PTSD. Implications for practice will be discussed along with suggested questions to ask parents and children to assess for exposure to trauma. J Pediatr Health Care. (2013) 27, e29-e38.