Isolated unilateral pulmonary artery agenesis is a rare congenital anomaly that may be complicated with hemoptysis, recurrent pulmonary infections or pulmonary hypertension. To our knowledge the occurrence of a coronary syndrome associated with a coronary-to-bronchial artery saccular aneurysmal collateralization has never been described before. A 44-year-old female presented a congenital right pulmonary artery agenesis associated with a hypotrophic and multicystic right lung complicated with recurrent bronchitis. This patient had a coronary syndrome for which the coronary artery imaging showed a coronary-to-bronchial artery collateralization with an aneurysm at this level. It gives rise to a coronary syndrome by coronary steal. Two bronchial collaterals arising from a diaphragmatic artery and the subclavian artery were also found on the computed tomography (CT)-scan. This last collateral also showed another saccular aneurysm. We first performed an embolization of those two aneurysms in order to decrease the risk of hemorrhage and coronary steal, before performing a right pneumonectomy. In this case, the surgery was indicated because of the pathological lung and the risk of postembolization ischaemia. The postoperative course was uneventful and the patient was doing well six months later.