We attempted to determine physician prescribing patterns of angiotensin-converting enzyme (ACE) inhibitors in patients who experienced a myocardial infarction, stratified by left ventricular function. We retrospectively reviewed drug therapy at discharge in 534 patients to assess prescription of ACE inhibitor therapy, including dosage. Thirty-four percent of patients were discharged taking an ACE inhibitor, of whom only 11% received recommended dosages. The drugs were prescribed more often for patients who had an ejection fraction below 40% than for those with an ejection fraction of 40% or above (54% vs 28%, p< 0.05). We conclude that ACE inhibitors are underprescribed for patients who experienced a myocardial infarction, illustrating the gap between clinical research and clinical practice, and the need for programs to ensure optimal medical management.