Despite substantial increases in smoking and intensified marketing of tobacco products in developing countries (1), efforts to prevent tobacco use through community-based approaches have been limited (2,3). In Thailand, an estimated 9 million children will become smokers, and more than 2 million will die prematurely as adults from smoking-related illnesses (1,4). Because of these risks, the Department of Community and Social Medicine, Mae Sot General Hospital (MSGH), and the Field Epidemiology Training Program (FETP) of the Thai Ministry of Public Health recently assessed the impact of community-based smoking-prevention efforts initiated by religious leaders. This report describes this program and summarizes the assessment.