BACKGROUND: RESEARCH ON THE EFFECT OF STRESS MANAGEMENT INTERVENTIONS ON THE COMMUNITY AT LARGE IS SCARCE. THIS STUDY AIMS TO ASSESS THE EFFECTIVENESS OF A STRESS-MANAGEMENT TRAINING PROGRAM ON REDUCING PERCEIVED STRESS LEVEL IN A LARGE POPULATION. METHOD: A LONGITUDINAL STUDY WITH MULTISTAGE CLUSTER RANDOM SAMPLING WAS PERFORMED IN 1999-2005 IN ISFAHAN, NAJAF-ABAD AND ARAK COUNTIES WITHIN THE CONTEXT OF ISFAHAN HEALTHY HEART PROGRAM. STRESS MANAGEMENT INTERVENTIONAL STRATEGIES WERE PERFORMED FOR SITES OF INTERVENTION ADJUSTED ACCORDING TO TARGET GROUPS. IN A 45-MINUTE HOME INTERVIEW DEMOGRAPHIC DATA, GENERAL HEALTH QUESTIONNAIRE AND A STRESS MANAGEMENT QUESTIONNAIRE WERE COLLECTED. DATA WERE ANALYZED BY T-TEST, LINEAR REGRESSION AND GENERAL LINEAR MODEL. RESULTS: TREND OF BOTH ADAPTIVE AND MALADAPTIVE COPING SKILLS AND GHQ SCORES FROM BASELINE TO THE LAST SURVEY WERE STATISTICALLY SIGNIFICANT IN BOTH INTERVENTION AND REFERENCE AREA (P£0.001). ADAPTIVE COPING SKILLS INCREASED CONSIDERABLY, WHILE MALADAPTIVE COPING SKILLS DECREASED SIGNIFICANTLY, ALSO STRESS LEVEL DECREASED SIGNIFICANTLY IN INTERVENTION COMPARED TO REFERENCE AREA. CONCLUSIONS: STRESS MANAGEMENT PROGRAMS COULD LOWER STRESS LEVEL IN COMMUNITY AND SHOULD BE PROMOTED AS PRIMARY PREVENTION PROGRAMS THAT TARGET STRESS AND COPING. THESE PROGRAMS NEED POSITIVE AND STRONG COOPERATION OF COMMUNITY POLICYMAKERS AND STAKEHOLDERS TO FACILITATE IMPLEMENTATION OF EVIDENCE-BASED INTERVENTIONS.