The article focuses on a review of the extant literature on post traumatic stress disorder (PTSD). Theoretical and clinical aspects of PTSD are considered. Issues concerning the diagnosis of PTSD are presented on the theoretical level. There is a description of the disorder and how it causes a significant impairment in functioning. The article also reviews the models of etiology of PTSD. There is a description of the conditioning model, as well as the emotional and cognitive processing in the etiology, and maintenance of the disorder. Risk factors are considered in the development of the disorder. On the clinical level, there is a description of the main inventories and questionnaires for assessing and evaluation patients with PTSD. Finally, there is a description of the current psychological treatments for PTSD, especially exposure therapies, anxiety management training and cognitive therapy, treatments that have proven to be effective in reducing PTSD in well controlled studies.