Angiotensin-converting enzyme inhibitors are proved, effective agents for the treatment of hypertension and congestive heart failure. New data suggest that angiotensin-converting enzyme inhibitors may be effective therapy for patients following acute myocardial infarction. Results from clinical trials, such as the Survival and Ventricular Enlargement trial, have demonstrated that captopril attenuates left ventricular enlargement, minimizes and/or prevents the subsequent development of overt congestive heart failure, and improves survival in patients with asymptomatic left ventricular dysfunction after myocardial infarction. Clinical reinfarctions and need for subsequent revascularization procedures were also reduced with captopril. In the Acute Infarction Ramipril Efficacy study, patients with clinically evident heart failure following acute myocardial infarction who received ramipril demonstrated a significant reduction in mortality and cardiovascular events. The mortality benefit in this study was evident within 30 days, possibly reflecting differences in patients studied (ie, population with high-risk heart failure in the Acute Infarction Ramipril Efficacy study as opposed to population with asymptomatic left ventricular dysfunction in the Survival and Ventricular Enlargement trial). Contrary results have been reported in another major postmyocardial infarction trial, the Cooperative New Scandinavian Enalapril Survival Study, which evaluated enalaprilat/enalapril maleate in unselected patients with acute myocardial infarction. This article reviews the recent trials using angiotensin-converting enzyme inhibition after myocardial infarction and will explore the reasons why angiotensin-converting enzyme inhibition seems to be beneficial in this clinical setting.