Coronary artery fistula (CAF) is a direct communication between a coronary artery and the lumen of any of the cardiac chambers, i.e. the coronary sinus, the pulmonary artery, the superior vena cava or the proximal pulmonary veins. The majority of these fistulas are congenital in origin although they may occasionally be detected after cardiac surgery. Congenital CAF is a rare anomaly and aneurysmal formation in the fistula is even rarer. Majority of CAFs are isolated lesions, however, congenital or acquired heart diseases may co-exist. Herein, we report a case of huge congenital aneurysmal right CAF connected to the right atrium in an Iraqi man of 62 associated with tuberculous effusive-constrictive pericarditis to whom off pump pericardiectomy was performed followed by ligation of right coronary artery and vein graft implantation to its posterior descending branch under cardiopulmonary bypass. To the best of our knowledge, such association was not previously reported. CAF can be repaired surgically with minimum risk and excellent outcome. Surgery is advised whenever coronary fistula is diagnosed unless it is very small to avoid the potential complications.