Background: Association of anxiety disorders and complex nature of Posttraumatic stress disorder (PTSD) entails examining and applying new treatments therapies. The aim of current study was to determine the effectiveness of cognitive training component in reducing symptoms of PTSD. Materials & Methods: This quasi-experimental study was conducted with pre-post test and follow- up design using control group from all veterans patients with PTSD who lived in Urmia. For this reason, 40 patients were randomly selected and divided into two equal experimental and control groups. Experimental group experienced 8 sessions of Wells’s metacognitive therapy. While the control group was only followed. Mississipi scale was used as a diagnostic tool and PCL checklist as well as metacognitive test used as evaluation tools in the pre-test, post-test and follow up after two months. The results were recorded. Result: Data were analyzed by multivariate covariance test (ANCOVA) and t-test. Our results indicated that there is a significant difference between mean metacognitive component’s scores of experimental and control groups in post-test and follow up(P<0/01). Experimental group also showed the significant decreas in total scores of general symptoms than the control in post- and follow- up test. Conclusion: These results showed that the metacognitive components in veterans with PTSD are disordered and applying metcognitive model of Wells will be effective on decreasing general symptoms of PTSD.