BACKGROUND: This study was designed to assess the effectiveness of stress management training in improving the ability of coping with stress in a large population.METHODS: Five cross-sectional studies using multistage cluster random sampling were performed on adults aged³19 years between 2000 to 2005 in Isfahan and Najafabad (Iran) as INTERVENTION cities and Arak, Iran as the control city within the context of Isfahan Healthy Heart PROGRAM. Stress management training was adapted according to age and education levels of the target groups. In a 45-minute home interview, demographic data, General Health Questionnaire (GHQ) and stress management questionnaires were collected. Data was analyzed by t-test, linear regression and general linear model.RESULTS: Trends of both adaptive and maladaptive coping skills and GHQ scores from baseline to the last survey were statistically significant in both INTERVENTION and reference areas (P<0.001). While adaptive coping skills increased significantly, maladaptive coping skills decreased significantly in the INTERVENTION areas. Furthermore, stress levels decreased significantly in the INTERVENTION compared to the reference area.CONCLUSION: Stress management PROGRAMs could improve coping strategies at the community level and can be considered in designing behavioral INTERVENTIONs.