Posterior urethral valves (PUV) are the most common cause of lower urinary tract obstruction in boys. They are usually suspected antenatally or soon after the birth as the cause of severe hydronephrosis, oligohydramnios, renal hypodysplasia, and kidney failure. In milder forms of PUV, the uncharacteristic symptoms occur later in childhood, adolescence, or even adulthood and cause diagnostic problems. The final diagnosis and causative treatment of PUV are possible due to cystourethroscopy. Nevertheless, as a consequence of the defect, valve bladder syndrome (VBS) occurs and requires long-term treatment. The authors present a case of a 14-year-old boy with a late diagnosis of PUV at the age of 7. Recurrent pyelonephritis and nonspecific voiding dysfunction were the first symptoms. Ultrasounds(US) were initially normal while videocystometry(VCM) showed the 3rd-grade right-sided vesicoureteral reflux (VUR), bladder diverticulum as well as discrete detrusor overactivity, and reduced bladder capacity without any signs of bladder obstruction. Bilateral post-inflammatory nephropathy completed the clinical picture. In urethrocystoscopy surprisingly PUV were found and incised. Due to recurrent urinary tract infections (UTIs) one year later the STING procedure was performed which resulted in the resolution of VUR. Despite this, the features of bladder dysfunction, requiring regular urodynamic evaluation and pharmacotherapy, persisted. Recurrent UTIs in boys may suggest urinary tract obstruction and PUV should be considered regardless of the patient's age. Early diagnosis and appropriate management may improve the prognosis.