Posterior urethral valves are known to be associated with considerable morbidity and mortality especially in the neonate. Recently the role of bladder dysfunction in the pathophysiology of renal function impairment and urinary incontinence after valve ablation has been questioned. From 1976 to 1986 we treated 50 male newborns with posterior urethral valves at our institution. Initial treatment in all cases consisted of bladder drainage by a urethral catheter, and correction of existing fluid and electrolyte abnormalities. Subsequent treatment was dictated by the degree of upper tract abnormalities and it included valve ablation alone in 24 patients, vesicostomy and later valve ablation in 8, valve ablation and later upper tract reconstruction in 14 and cutaneous ureterostomy in 4. Followup ranges from 2 to 12 years (mean 6.8). Long-term renal functional impairment was related to the serum creatinine at age 1 year. If the serum creatinine was below 1.0 mg.% all patients (31) had normal values at long-term followup and if it was greater than 1.0 mg.% (19) then only 7 patients had normal values at followup. Urinary continence was assessed in 42 patients and it was normal in 34 (81%). The etiology of incontinence in the remaining 8 patients was bladder dysfunction in 6 and sphincter incompetence in 2. Those patients with urinary incontinence also had a high incidence of upper tract abnormalities (6 of 8, 75%) compared to continent valve patients (10 of 34, 29%).