A 36-year-old man presented with left lumbosacral region pain and 2 days of oliguria. Acute renal failure of a solitary pelvic kidney was diagnosed after a blood creatinine test, color Doppler ultrasonography, and magnetic resonance imaging. The cause of the acute renal failure was not clear; however, acute ureteral obstruction was presumed and emergency surgery was performed. The unusual anatomy of the kidney required specific management to find and relieve the cause of the obstruction. We found and cleared an upper ureteral stone by endoscopic surgery after exploring the kidney through open surgery.