Posttraumatic stress disorder (PTSD) has been the subject of growing recognition since its inception in 1980. Owing in part to the relatively recent inclusion of PTSD in the psychiatric nomenclature, research is only beginning to address its treatment in methodologically rigorous studies. In this review, we discuss issues such as prevalence of trauma and of PTSD, and gold standards for treatment outcome research. We then critically review the extant literature on the treatment of PTSD. Finally, we include a discussion of issues specific to various trauma populations and factors that may influence treatment efficacy across types of trauma.