Since the introduction of posttraumatic stress disorder (PTSD) into the Diagnostic and Statistical Manual of Mental Disorders, Third Edition (DSM-III; American Psychiatric Association, 1980), considerable research has demonstrated the efficacy of several cognitive–behavioral therapy (CBT) programs in the treatment of chronic PTSD. Among these efficacious treatments is exposure therapy. Despite all the evidence for the efficacy of exposure therapy and other CBT programs, few therapists are trained in these treatments and few patients receive them. In this article, the authors review extant evidence on the reasons that therapists do not use these treatments and recent research on the dissemination of efficacious treatments of PTSD.