BACKGROUND The Cooperative Cardiovascular Project (CCP) was initiated by the Health Care Financing Administration to improve the quality of care for Medicare beneficiaries admitted to the hospital with acute myocardial infarction (AMI). Four peer review organizations formed the CCP Best Practices Working Group (Working Group) to identify effective intervention strategies that enable a hospital staff to improve AMI care. METHODS The peer review organization in each state was asked to identify six hospitals with exemplary quality improvement (QI) plans for AMI care; 33 states responded. Data about the hospitals' baseline performance on the CCP quality indicators and components of the QI plans were collected from each hospital. Thirty-six of 40 randomly selected hospitals from this group were interviewed. RESULTS The Working Group identified 191 hospitals in 33 states with exemplary QI plans. Administration of thrombolytic therapy and aspirin were the quality indicators most commonly addressed. Staff education, development or revision of clinical pathways and standing orders, and ongoing data collection were the most common QI plan components. The need to develop interdisciplinary teams and to identify a strong physician champion for the QI efforts were the most common recommendations for other hospitals considering implementation of the CCP. CONCLUSIONS The CCP stimulated interest in QI activities for AMI care in the institutions identified for the Working Group. The characteristics of the hospitals' improvement plans were consistent with those identified by contemporary leaders of clinical QI as central to improving care. These plans focused on changes in clinical processes, deployment of interdisciplinary teams, identification of project champions, and ongoing data collection to assess and improve quality of care.