We analyzed the admission electrocardiogram in 109 patients with inferior wall acute myocardial infarction in an attempt to determine the infarct-related artery (IRA). The presence of ST depression in leads V1 or V2 had a high sensitivity for predicting the left circumflex artery as the IRA. The lack of ST depression in V1 or V2 had a high negative predictive value for excluding the left circumflex artery as the IRA.