A 65-year-old man with stable angina refractory to medical therapy and with a low-threshold myocardial ischemia at ECG stress testing was referred for coronary angiography. The coronary angiogram showed an ostial subocclusive stenosis of a developed first diagonal branch located just upstream of a subocclusive stenosis of the mid left anterior descending (LAD) coronary artery, occluded distally, and a coronary collateral for LAD from a developed right ventricular branch arising with separate ostia from the right sinus of Valsalva. We discuss the diagnostic interpretation of this coronary anomaly and some aspects regarding the percutaneous treatment of bifurcations.