Background: Acute stress disorder (ASD) predicts the development of posttraumatic stress disorder (PTSD), which in some sufferers can persist for years and lead to significant disability. We carried out a review of randomized controlled trials to give an update on which psychological treatments are empirically supported for these disorders, and used the criteria set out by Chambless and Hollon [1998: J Consult Clin Psychol 66:7–18] to draw conclusions about efficacy, first irrespective of trauma type and second with regard to particular populations. Methods: The PsycINFO and PubMed databases were searched electronically to identify suitable articles published up to the end of 2008. Fifty-seven studies satisfied our inclusion criteria. Results: Looking at the literature undifferentiated by trauma type, there was evidence that trauma-focused cognitive behavioral therapy (CBT) and eye movement desensitization and reprocessing (EMDR) are efficacious and specific for PTSD, stress inoculation training, hypnotherapy, interpersonal psychotherapy, and psychodynamic therapy are possibly efficacious for PTSD and trauma-focused CBT is possibly efficacious for ASD. Not one of these treatments has been tested with the full range of trauma groups, though there is evidence that trauma-focused CBT is established in efficacy for assault- and road traffic accident-related PTSD. Conclusions: Trauma-focused CBT and to a lesser extent EMDR (due to fewer studies having been conducted and many having had a mixed trauma sample) are the psychological treatments of choice for PTSD, but further research of these and other therapies with different populations is needed. Depression and Anxiety, 2009. © 2009 Wiley-Liss, Inc.