The left internal mammary artery (LIMA) has been the conduit of choice in coronary artery bypass grafting (CABG). Atresia of the LIMA is a common finding after CABG in patients with less than critical disease of the native vessel. However, it is extremely rare for an atretic LIMA to restore its normal caliber after progression of native coronary artery disease. We report a patient in whom the LIMA was occluded 2 years after CABG, but was found to be completely patent 5 years later, after worsening of the left anterior descending artery disease.