Although exceedingly unusual, six significant late and potentially lethal complications of coronary perfusion have been observed. In five patients, angina was a sequel of aortic valve replacement, and in the sixth, ventricular tachycardia occurred. Coronary angiography revealed proximal coronary artery stenosis not present in preoperative study in five of the patients, and a dissecting aneurysm of the right coronary artery in the sixth. In four patients, the findings were confirmed during successful reoperation. These patients illustrate the urgent need for repeating coronary angiography when angina or serious arrhythmia occurs late following aortic valve replacement.