Background: The optimal percutaneous interventional strategy for dealing with significant non-culprit lesions in patients with multivessel disease (MVD) with acute myocardial infarction (AMI) at presentation remains controversial.Methods: A total of 820 patients treated with primary angioplasty for AMI between 1998 and 2002 were classified in groups of patients with single vessel disease (SVD) or MVD (> or =70% stenosis of > or =2 coronary arteries). Patients with MVD were subdivided in 3 groups on the basis of the revascularization strategy: 1) patients undergoing percutaneous coronary intervention (PCI) of the infarct-related artery (IRA) only; 2) patients undergoing PCI of both the IRA and non-IRA(s) during the initial procedure; and 3) patients undergoing PCI of the IRA followed by staged, in-hospital PCI of the non-IRA(s).