An 80-year-old woman with pre-existing complete right bundle branch block presented with severe chest pain. The 12-lead electrocardiogram, together with right-sided chest leads, showed complete right bundle branch block and ST segment elevation in leads II, III, aVF, V5, V6 and V4R to V6R. These electrocardiographic abnormalities indicate acute 'Q wave' inferolateral and right ventricular infarction coexisting with right bundle branch block.