OBJECTIVE To evaluate the safety and efficacy of nitinol stents and the Detour extra-anatomical ureteral bypass graft in treatment of ureteral stenosis after kidney transplantation. METHODS Eighteen kidney transplant recipients with complex stenosis caused by failure of primary treatment or with high surgical risk or a poorly functioning graft (serum creatinine concentration >2.5 mg/dL) were treated using antegrade percutaneous implantation of nitinol stents (n = 16) or extra-anatomical ureteral bypass grafts (n = 3); 1 patient was treated with both techniques. RESULTS Mean (range) follow-up of ureteral stents was 51.2 (3-118) months. Patency rate at last follow-up, resumption of dialysis therapy, or death was 75% (12 of 16 patients). In 4 patients (25%), stent occlusion developed, which was treated using a double-J catheter in 2 patients, stent removal and pyeloureterostomy using the native ureter in 1 patient, and implantation of an extra-anatomical bypass graft in 1 patient. Mean follow-up in patients with extra-anatomical ureteral bypass grafts was 32 (8-64) months. One patient developed a urinary tract infection, and another had encrustation with obstruction. CONCLUSIONS Use of nitinol ureteral stents and extra-anatomical ureteral bypass grafts is a safe and effective alternative to surgery for treatment of post-kidney transplantation ureteral stenosis in patients with chronic graft dysfunction, those at high surgical risk, and those in whom previous surgical treatment has failed.