During the past 6 years, 50 patients underwent percutaneous transluminal coronary angioplasty (PTCA) of a narrowed coronary anastomosis of a left internal mammary artery (LIMA) graft or PTCA of a left anterior descending coronary artery stenosis via LIMA grafts at the investigators' institution. The success rate was high at 88%. Thirty-four of the 44 successfully treated patients (77%) underwent repeat angiography, which showed restenosis in 14 patients (41%). In cases of stent implantation at the coronary LIMA graft anastomosis angioplasty site, the restenosis rate was 80%, but it was only 14% in cases of pure balloon dilation (p = 0.001). Therefore, in cases of coronary LIMA graft anastomosis, stent implantation should be avoided, because it implicates an excessively high restenosis rate.