Prolonged exposure (PE), the most widely used form of psychological therapy utilized to treat PTSD, has become the PTSD therapy of choice. The approach and protocol is described in detail for PE, noting that the average response rate is approximately 60–70%. While almost all PE studies have been done among males developing PTSD after war trauma, PE has also shown excellent results when used with patients who have failed other treatment approaches, in those meeting criteria for complex PTSD, and in the subset of PTSD patients also diagnosed with substance abuse disorder (SUD). Unfortunately, dropout rates from PE protocols are quite high (52% in some studies). This is due in part to the aversive nature of PE for both patient and therapist. Dropout rates can be reduced by increasing intensity and limiting time of the therapy process. An alternative PE approach, narrative exposure therapy, is also APA recommended as an approach for treating PTSD. Prolonged exposure is now marketed directly to consumers as the “effective” treatment for PTSD. The evidence indicates that while PE can produce better results than many other approaches, many unanswered questions remain. These include questions as to long-term persistence of effects, value in other at-risk populations, comparative efficacy to other effective PTSD therapies, negative side effects, as well as the question as to what component of treatment success can be attributed to treatment avoidance. Little data supports the use of PE in group, Internet, and AI protocols.