RVI is a frequent occurrence in the setting of an acute inferoposterior myocardial infarction and its early recognition has important therapeutic and prognostic implications. Because of this, diverse invasive and noninvasive diagnostic techniques have been investigated to identify patients with RVI. Electrocardiography is the most available, simple, and objective of these techniques. Numerous ECG signs of RVI have been described and some of them, especially ST segment elevation and patterns of necrosis (QS, QR) in the right precordial leads (V3R to V5R), have a very high sensitivity, specificity, and positive predictive value for the detection of RVI. ST segment elevation in lead V4R is also helpful in identifying the occluded coronary artery in patients with acute myocardial infarction, which could have great importance in their management. Hence, a 12-lead ECG with the right precordial leads (V3R to V6R) should be a routine part of the initial evaluation of patients with clinical suspicion of acute inferior myocardial infarction. This article reviews the value, limitations, and pathogenesis of the ECG manifestations of RVI.