We herein describe a 57-year-old man with coronary-pulmonary artery fistulas that had abnormal connections between the left common carotid artery and the left internal mammary artery. The patient was treated with percutaneous coil embolization using antegrade (via the coronary artery) and retrograde (via the pulmonary artery) approaches. Coronary artery fistulas have diverse anatomical variations, and it is important to thoroughly evaluate the anatomy before beginning any mode of treatment, surgical or endovascular. In the case reported herein, multislice computed tomography played a pivotal role in the preprocedure evaluation.