We report a 10-year-old boy with and unstable bladder, bilateral epididymitis, urge incontinence, bed wetting, and unilateral reflux. Previously, he complained of urinary incontinence and was operated on elsewhere with Y-V plasty in the bladder neck and pulling out a balloon catheter through the urethra. Following the surgery the urinary force was weakened, incontinence got worse and bilateral epididymitis broke out frequently. Since the patient was refractory to anti-cholinergic medicine, sacral nerve block, antireflux operation and narrowing the bladder neck were attempted. The surgery was successful in eradicating reflux and urinary tract infection, but failed to normalize the extremely widened bladder neck. Urge incontinence and bed wetting recurred 11 months after the sacral block, which was effective in a selected patient. We believe that Y-V plasty at the bladder neck should not be indicated for a patient with bladder dysfunction closely related to an unstable bladder.