In brief: This paper discusses ureteropelvic junction obstruction and presents a case report of a young male athlete with a 13-year history of vague abdominal pain associated with long-distance running. Ureteropelvic junction obstruction was found to be the cause of his pain. A review of similar cases showed a significant number of patients with vague abdominal pain produced by ureteropelvic junction obstruction. While IVP is the standard for diagnosis, ultrasonography can be a useful screening test. The authors conclude that ureteropelvic junction obstruction should be considered for patients with abdominal pain.