BACKGROUND: 'Hartslag Limburg', a cardiovascular diseases (CVD) prevention programme, integrates a community strategy and a high-risk strategy to reduce CVD risk behaviours. This article presents the results of the effect evaluation study of the community intervention at the organizational level. Organizational changes were an intermediate goal of the Hartslag Limburg community intervention, as these are assumed to be a prerequisite for changes at the individual level. METHODS: A baseline-post-test control group design was used. The baseline measurement was conducted in 1998 and the post-test measurement in 2001. At baseline, 700 organizations were selected in the Maastricht region, and 577 in a control region. All organizations that were potentially significant agents in health-promoting activities were included. Data on organizational involvement in health-promoting activities were gathered by means of structured questionnaires, and sent to organization representatives by mail. RESULTS: The overall post-test percentage of organizations involved in at least one activity relating to physical activity was higher in the Maastricht region than in the control region. Furthermore, the number of activities per organization involved in activities relating to healthy eating, smoking behaviour or physical activity was higher in the Maastricht region than in the control region at post-test. CONCLUSIONS: This study provided valuable information about organizational involvement in health-promoting activities, as well as important information to consider in future research in this area. Due to the limitations of the study, the importance of measuring change at different social levels in community-based programmes, and the scarcity of effect studies of community interventions at the organizational level, further research on this subject is warranted.