Tehran University of Medical Sciences The Research in Heart Yield and Translational Medicine (RHYTHM) 3115-7270 15 4 2020 10 31 189 194 Mehdi Peighambari Rajaie Cardiovascular, Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran. Marziyeh Pakbaz Rajaie Cardiovascular, Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran. Azin Alizadehasl Rajaie Cardiovascular, Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran. Saeid Hosseini Rajaie Cardiovascular, Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran. Hamidreza Pouraliakbar Rajaie Cardiovascular, Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran. 2018 10 09 2020 09 13 Coronary artery fistulas constitute a rare anomaly defined as an abnormal communication between a coronary artery and a great vessel or any cardiac chamber. The majority of these fistulas arise from the right coronary artery and the left anterior descending coronary artery; the circumflex coronary artery is rarely involved.  We present an unusual case of a coronary artery fistula in a middle-aged woman who presented with symptoms of heart failure and abnormal auscultation. Echocardiography and conventional and computed tomography angiography showed that the coronary fistula originated from the left circumflex coronary artery and drained majorly into the right ventricle. Given the complex anatomy of the fistula, we managed it surgically rather than percutaneously. There were no complications early after surgery and at 1 year’s follow-up. https://rhythm.tums.ac.ir/index.php/jthc/article/view/970 https://rhythm.tums.ac.ir/index.php/jthc/article/download/970/943