We report a case of vaginal reconstruction using a flap from urinary bladder in a young girl. This girl was born with cloacal malformation and hemivaginas connected to the urinary bladder. Repeated urinary tract infection and vesicoureteral reflux were noted. At the age of 9 months, she received posterior sagittal anorectoplasty for rectum pull-through, but the urogenital part was not corrected. She had repeated urinary tract infection. Detrusor areflexia and large bladder volume were demonstrated by cystometry. Cystoscopy showed a common channel longer than 3 cm. Urogenital reconstruction was performed at 14 months of age. A part of the urinary bladder wall, which was connected to the vaginas, was used to lengthen the vagina so that the latter was able to pull down to the perineum. The patient received vaginal dilatation and intermittent catheterization after the surgery.