Although obesity was initially considered a relative contraindication for laparoscopy, the retroperitoneal approach has been reported to be safe and effective for such patients during renal and adrenal surgery. We report a case of successful retroperitoneoscopic radical nephrectomy in a super-obese patient (body mass index 77 kg/m²) with a 12-cm renal tumor. The operative time was 3 hours, and the estimated blood loss was 100 mL. The patient was discharged home 36 hours after surgery. No intraoperative or perioperative complications occurred. The pathologic examination revealed renal cell carcinoma, and all surgical margins were negative (pT2N0M0). The patient returned to normal activities 3 weeks postoperatively.