An 82-year-old man with a history of renal transplantation 14 years earlier presented with acute obstructive renal failure secondary to inguinal herniation of the urinary bladder complicated by ureteroneocystostomy entrapment. After percutaneous nephrostomy tube and endoscopic stent placement, the bladder was reduced and the hernia repaired with the use of a preperitoneal mesh. The postoperative course was uneventful and the renal function returned to normal. Inguinal herniation of the transplant ureter is a rare cause of hydronephrosis, but it has been described in the literature. Bladder hernias do usually not cause urologic complications in the nontransplanted patient, but they can present as an emergency after renal transplantation.