We report an unusual case of a 3-year-old girl with multiple nephrogenic adenomas in the urinary bladder following previous surgical intervention. When she was 6-month-old, right vesicoureter-alreflux (VUR) and left marked hydronephrosis with ectopic urethral opening were found. The left renal pelvis and ureter were incompletely duplicated with a short common segment. Bilateral ureterocystoneostomy and closure of ectopic opening of the left ureter were performed. Left ureteral orifice resulted in double barreled pattern. Postoperative voiding-cystourethrography revealed VUR in the ureter belonging to the lower part of the left kidney. At the age of 3 year, cystoscopic examination revealed multiple papillary lesions in the urinary bladder. These lesions were resected transurethrally and the pathologic diagnosis was nephrogenic adenoma. The patient is the 27th case of nephrogenic adenoma of bladder reported in the Japanese literature.