Renal allograft rupture (RAR) is a rare but serious complication of renal transplantation. The most common cause of RAR is acute rejection but other causes have increased in frequency with advances in immunosuppressive therapy. We report a patient with RAR attributed to coughing while asleep. A 53-year-old male received a living-donor renal transplantation for end-stage renal failure due to diabetic nephropathy. The clinical course was satisfactory, and he was discharged on the 12th postoperative day with a serum creatinine level of 1.24 mg/dl. On the 24th morning, he felt sudden swelling and pain over the incision area soon after a big cough. Ultrasound and computed tomography revealed a perinephric hematoma. Emergency surgical exploration showed complete laceration of the abdominal fascia and 4-cm rupture at the anterolateral aspect of the kidney. High intra-abdominal pressure when coughing had torn the fascia, and the graft appeared to have ruptured under the fascial tension. Bleeding was controlled with a polyglactin 910 2/0 mattress parenchymal suture enforced with application of a fibrin tissue-adhesive collagen fleece. Twelve months after the repair, the patient's renal function was stable with a serum creatinine level of 1.3 mg/dl.