Angiographic restenosis occurs in 30% to 50% of patients after percutaneous transluminal coronary angioplasty (PTCA) with 20% to 30% target vessel revascularization at one year, and is associated with increased morbidity, mortality and health care costs. Intracoronary stents are the first line of therapy against restenosis after angioplasty. Depending on lesion morphology and location, stents can reduce restenosis and target lesion revascularization (TLR) by 20% to 30%. Obstructive coronary lesions in vessels with a diameter larger than 3.0 mm should be stented. The benefit of stenting in vessels smaller than 3.0 mm is controversial, with the BESMART (Bestent in Small Arteries) and ISAR-SMART (Intracoronary Stenting or Angioplasty for Restenosis Reduction in Small Arteries) studies demonstrating conflicting results. Chronically occluded and subtotal vessels should be stented after PTCA. Obstructive lesions in saphenous vein grafts should be stented. It is preferable to stent ostial lesions after PTCA. Restenosis can occur in 15% to 25% of patients within 6 months of stent placement. Initial approach to focal in-stent restenosis is to repeat PTCA. Patients with diffuse restenosis may require debulking prior to PTCA to improve acute results. "Stenting within-stent" has not proven beneficial unless there is diffuse in-stent restenosis, neointimal prolapse or vessel dissection during PTCA. There are no pharmacologic therapies approved by the Food and Drug Administration available to treat restenosis at present. Brachytherapy, gamma or beta, is an effective adjunctive therapy that can reduce recurrent in-stent restenosis by 40% to 70%. Patients at high risk for recurrent in-stent restenosis (proliferative or total occlusion pattern) can be considered for brachytherapy to treat the first episode of in-stent restenosis. Patients with focal in-stent restenosis should be treated with brachytherapy after multiple recurrences of in-stent restenosis. Emerging therapies for treatment of restenosis include antiproliferative-coated stents and photoangioplasty.