BACKGROUND Beneficial effect has been reported from angiotensin converting enzyme (ACE) inhibition after acute myocardial infarction (AMI) in several experimental and large clinical studies showing improvements in haemodynamics, left ventricular remodelling and mortality. However, this benefit has not been prospectively evaluated after AMI effectively reperfused using current coronary recanalization techniques. OBJECTIVE The clinical relevance of reperfusion therapies including thrombolysis or percutaneous transluminal coronary angioplasty relates to their ability to limit infarct size and left ventricular dysfunction and reduce infarct-related morbidity and mortality. The clinical issue is to determine whether ACE inhibitors should be routinely proposed as an adjunct therapy in patients with a patent infarct-related vessel after AMI. Three placebo-controlled randomized trials addressed this issue in evaluating the left ventricular remodelling process (i.e. left ventricular volumes and ejection fraction changes) during a 3 to 4-month follow-up period. The Captopril and Thrombolysis Study and the Captopril plus Tissue plasminogen activator after Myocardial Infarction trials failed to show any significant preventive effect of early captopril therapy on remodelling in patients admitted for anterior AMI and treated with conventional use of streptokinase and alteplase, respectively. In the Salvage from Perindopril in Reperfused Infarction Trial, no beneficial effect on global left ventricular remodelling was observed from perindopril therapy in a population with effective myocardial reperfusion confirmed at angiography and moderately depressed left ventricular function. However, in this study ACE inhibition seemed to favourably alter remodeling in a subgroup of AMI patients with anterior location and large infarct size despite successful reperfusion. CONCLUSIONS Recommendation for ACE inhibition as a routine adjunct therapy to reperfusion techniques is not supported by current data on short-term left ventricular function changes.