An angiographically visible coronary to bronchial artery anastomosis was found in seven (0.12%) of 6045 patients with noncyanotic cardiopulmonary disease who underwent coronary angiography between 1989 and 1995. Aortitis syndrome was associated with four patients, whereas pulmonary embolism, aortic regurgitation and vasospastic angina were the diagnoses in the others. Coronary stenotic lesions were not observed in any patients. In five of six patients who underwent pulmonary perfusion scintigraphy, perfusion defect was observed in the area supplied by the bronchial artery, which had the anastomosis to the coronary artery. In each patient this anastomosis seemed to function as collateral circulation, compensating for decreased perfusion in either the lung or the heart. When coronary to bronchial artery anastomosis is found, ischemic conditions in either the lung or the heart are likely.