Infundibulopelvic dysgenesis is a rare condition characterized by congenital malformation of the pelvicalyceal system. We present the case of an 18-year-old boy with chronic intermittent right flank pain and cystic dilation with parenchymal thinning on ultrasonography. The left kidney was normal. The patient denied dysuria, constipation, and history of UTIs or renal calculi. Cystoscopy with retrograde pyelogram showed marked stenosis of the right pelvicalyceal system and anatomy unfavorable to stenting. The patient's symptoms were unresponsive to conservative management. Reconstruction of the right collecting system was unsuccessful and a simple nephrectomy was performed, which led to complete resolution of his symptoms.