Posterior Urethral Valve (PUV) is a pathology that causes infravesical obstruction in infants and mostly causes irreversible problems in kidney and bladder functions secondary to obstruction. PUV is a fibrous membrane located in the posterior urethra, covered with uroepithelium on both sides, without a muscle layer. In PUV classification, the classification defined by Young in the 1900s is still used today. Young defined PUV types in three different classes. Type I PUV (90–95%), Type 2 PUV, Type 3 PUV. Clinical presentation varies depending on age. Although the average age at diagnosis was around 8 years in the first publications about this disease, nowadays, the diagnosis is made in the womb in a very high proportion of patients (40–60%) due to the much more common use of ultrasonography during pregnancy. The presence of bilateral ureterohydronephrosis, a thick-walled non-emptying bladder and an enlarged posterior urethra (keyhole sign) in the boys, especially after the 24th antenatal week, are diagnostic findings. The bladder of every newborn with PUV diagnosis or suspected PUV in antenatal USG should be decompressed with a feeding tube of appropriate thickness (5 FR-8FR) after the birth immediately. The prostatic urethra is severely dilated due to valvular obstruction and the bladder neck is hypertrophied. Therefore, urethral catheterization may be difficult as the catheter may be inserted in the prostatic urethra. It is recommended to check with USG whether the catheter has passed into the bladder. The inflated catheter balloon may cause obstruction in the ureteral orifices in the thick-walled bladder, and may also cause spasm in the bladder, which may adversely affect urinary drainage. Therefore, it is not recommended to use a Foley catheter in the first attempt. Primary valve ablation is the preferred modality of treatment. It is physiological as it allows the bladder to continue cycling. The miniaturization of pediatric endoscopes allows for majority of valves to be ablated primarily.