STUDY OBJECTIVE: To develop and evaluate a peer review group (PRG) meeting using feedback data on a patient level to improve the quality of drug therapy for prevention of recurrent myocardial infarction. DESIGN: Prospective follow-up study. DATA SORCE: General practitioners’ computerized patients records (intervention patients) and the PHARMO record linkage system (controls). PATIENTS: Forty patients in the intervention group and 1030 control patients; both groups had documented myocardial infarction. INTERVENTION: The intervention, which was based on the principles of group academic detailing, consisted of scoring current cardiovascular treatment on separate forms for each patient, presenting an overview of, and discussing, evidence-based treatment after myocardial infarction, defining the target population, formulating a binding consensus, and identifying patients who were eligible for improvement of pharmacotherapy. MEASUREMENTS AND MAIN RESULTS: Drug therapy and adherence to the newly formulated PRG consensus were assessed at baseline and 1 year after the intervention. Of the patients who received the intervention and were not treated according to the PRG consensus at baseline, 40% received treatment according to the consensus 12 months after the PRG meeting. In the control group, the proportion of patients was 9.5% (prevalence ratio 4.2, 95% confidence interval 1.8-9.7). CONCLUSION: Peer review group meetings can be a valuable tool for improving pharmacotherapy after myocardial infarction.