We describe the case of an 89-year-old woman who developed severe left main coronary artery stenosis shortly after transcatheter aortic valve implantation (TAVI) with the Medtronic CoreValve Revalving System. Urgent coronary angiography revealed the protrusion of a large calcium nodule of the native valve as the cause of left main narrowing, which was treated with bare-metal stent implantation. Angiographic and intravascular ultrasound findings at follow-up are reported. This case describes one of the mechanisms of a dreadful complication of TAVI and its difficult management.