Abstract: Posttraumatic stress disorder (PTSD) is a chronic psychological disorder that can develop after exposure to a traumatic event. This review summarizes the literature on the epidemiology, assessment, and treatment of PTSD. We provide a review of the characteristics of PTSD along with associated risk factors, and describe brief, evidence-based measures that can be used to screen for PTSD and monitor symptom changes over time. In regard to treatment, we highlight commonly used, evidence-based psychotherapies and pharmacotherapies for PTSD. Among psychotherapeutic approaches, evidence-based approaches include cognitive-behavioral therapies (e.g., Prolonged Exposure and Cognitive Processing Therapy) and Eye Movement Desensitization and Reprocessing. A wide variety of pharmacotherapies have received some level of research support for PTSD symptom alleviation, although selective serotonin reuptake inhibitors have the largest evidence base to date.