Poor autobiographical memory specificity is a cognitive marker of posttraumatic stress disorder (PTSD) and an independent predictor of poor prognosis. This pilot randomized controlled trial investigated the efficacy of MEmory Specificity Training (MEST) (an intervention aimed at ameliorating specificity problems) on autobiographical memory recall and PTSD symptoms. Iranian combat veterans with PTSD were randomly assigned into the MEST (. n=12) or control (. n=12) group. At baseline, groups completed Farsi versions of the Autobiographical Memory Test and Impact of Event Scale-Revised. The intervention group then had four, weekly, group sessions of MEST. The control group had no additional contact. All measures were re-administered post-intervention and at three-month follow-up. The MEST group generated significantly more specific memories and had significantly fewer PTSD symptoms following training and at follow-up than the control group. Findings suggest MEST is a promising intervention for the treatment of PTSD.