Circumcaval (retrocaval) ureter is a very rare vascular (venous) anomaly caused by an error in the embryonic development of the inferior vena cava in which an embryologically normal ureter becomes entrapped behind the inferior vena cava causing varying degrees of upper urinary tract hydronephrosis. Herein, the current study presents a case report of a 19-year-old Libyan male, single patient, who presented with right flank pain and dysuria of one-year duration. On abdominal examination, he had tenderness on the right renal angle. His laboratory investigations (Hematological and biochemical) were within normal limits. Urine analysis showed Escherichia coli infection, which was treated with antibiotics. His workup, including abdominal ultrasonography, showed a moderate degree of hydronephsis. Intravenous urogram showed typical reverse "J" Shaped (fish-hook) deformity and dilatation of the proximal ureter and hydronephrosis on the right side. He underwent the right ureteroureterostomy through a conventional midline approach. He passed an uneventful post-operative course and had a good outcome.