A circumflex artery originating from an ostium apart from the left main artery is one of the most common coronary artery anomalies. However, a dual origin of the circumflex artery is an extremely rare anomaly. We describe a 55-year-old male patient admitted to our clinic with the diagnosis of unstable angina. Angiography revealed twin circumflex arteries: one from the left main artery and the other from the proximal right coronary artery and a stenotic left anterior descending coronary artery (LAD). The patient was treated with percutaneous coronary intervention on the LAD lesion. His overall condition was good at 2 weeks' follow-up.