Acute renal failure is characterized by rapidly disruption in kidney function and postrenal causes typically result from obstruction of urinary flow. Multiple etiologies were described for acute renal failure, but labial fusion in postmenopausal female is a quite rarely encountered pathology among postrenal causes. Only a few cases have been presented in postmenopausal women presenting with urinary retention. We present a case with acute renal failure due to complete labial fusion in a postmenopausal woman and its treatment.