It is rare to observe ST elevation in anterior derivations caused by right ventricular branch occlusion. We described the case of a patient with unstable angina who developed acute right ventricular myocardial infarction with ST-segment elevation in anterior precordial leads (V(1)-V(4)) shortly after coronary angiography. Coronary angiogram revealed total occlusion of the right coronary artery (RCA) proximally to the right ventricular branch. This reminds us that the presence of diffuse ST-segment elevation in the precordial leads could be due to acute RCA occlusion. The differentiation of these two entities is important, as their therapies are quite different.