Interest in the range of psychological reactions that follow exposure to traumatic events has gained much ground in recent years, expanding to take into account the broader impact of mass trauma on populations as a whole. The present article provides an overview of the diverse range of events subsumed under psychological traumas, and the acute and long-term psychological consequences of such experiences. The relevance of Western conceptualizations of traumatic stress reactions to other cultures is also discussed. We describe mental health interventions after traumatic events including approaches used in the immediate aftermath of a trauma and pharmacological and psychological therapy that addresses more long-term difficulties. We also highlight some key issues that are distinctive to particular populations exposed to trauma, for example, refugees, torture survivors, and children.