A coronary artery fistula (CAF) is an abnormal vascular connection between the coronary arteries and the cardiac chambers or major vessels. Although rare, CAFs can lead to substantial coronary morbidity and mortality. This study outlines the surgical management of a CAF originating from the left coronary artery and connecting to the right atrium, in a patient experiencing angina with a marked left-to-right shunt. The surgical approach involved ligation of the coronary artery and reduction of the aneurysmal portion, resulting in the patient’s uneventful recovery.