Posterior urethral valve disease can be detected in the fetal period, or in some cases in the newborn or infant, and there are individual differences in whether a diagnosis can be obtained prenatally. Posterior urethral valves are membrane folds located in the posterior urethra. Posterior urethral valve disease is the most common cause of male urethral obstruction in newborns, occurring in approximately 1 in 4,000 to 8,000 pregnancies. In developed countries, the diagnosis of posterior urethral valvulopathy can be obtained by prenatal ultrasonography in about 1/3 to 1/2 of cases. Hydrocele, bladder dilatation and posterior urethral dilatation can be seen on ultrasound, suggesting posterior urethral valvulopathy. In addition to this, some are also diagnosed in the postpartum neonatal or infantile period.