The internal mammary artery (IMA) is currently the best graft for coronary bypass surgery and is therefore preferentially anastomosed to major arteries, usually the left anterior descending (LAD) artery. This graft may develop a stenosis, most often at the distal anastomosis. Ostial stenoses are rare and their pathophysiology uncertain. While angioplasty of distal anastomotic lesions provides adequate results, the very small number of published cases of angioplasty of ostial lesions explains the lack of knowledge on results of this type of procedure. The authors report six procedures of this type on five patients, including two with stenting. The primary success rate was 100%, with only one hospital complication in the form of pulmonary edema. Mean follow-up for 35 months revealed one sudden death due to probable restenosis, another death 3 years after angioplasty from rapid fatal shock without complementary investigation, and one case of unstable angina secondary to intrastent restenosis. These results suggest that this type of angioplasty is technically feasible with low risk, and that the restenosis rate seems relatively high, potentially presenting as sudden death, in the same way as unprotected dilatation of the native left main artery. A very close clinical follow-up of these patients is therefore necessary, with angiographic control in case of suspected ischemia.