A 52-year-old woman with Takayasu arteritis developed acute coronary syndrome and received percutaneous coronary intervention (PCI). The patient experienced restenosis three times even with drug-eluting stent (DES) implantation. We started steroid administration after the fourth PCI to reduce inflammation due to autoimmunity. With DES and a steroid combination, the patient remained free of chest pain, and a follow-up angiography demonstrated good patency of the stent site. Since in-stent restenosis may result from a complicated combination of neointimal proliferation and autoimmune mechanisms, physicians should consider a combination of DES and a steroid for the treatment of coronary artery disease in Takayasu arteritis.