This chapter reviews the evidence for psychological and pharmacological approaches to treating people with adverse psychological reactions after disaster. Posttraumatic stress disorder (PTSD) is the most commonly identified, and the disorder is characterized by three clusters of symptoms, including reexperiencing of the traumatic event, avoidance and numbing, and hyperarousal. Rates of PTSD are high in the initial months after a disaster, but most become noncases in the subsequent months. Short-term interventions are primarily designed to promote safety, assist coping, and stabilize the individual and their environment. Psychological debriefing has been the model approach to reducing the risk for chronic PTSD after disasters. The chapter also reviews the available evidence on treating posttraumatic disorders that can arise in the intermediate phase after a disaster. The World Wide Web is providing some promising avenues to provide cognitive-behavior therapy (CBT) to people who cannot access formal mental health services.