The optimal treatment for large, impacted, proximal ureteral stones remains controversial. We report our experience and compare treatment outcomes in patients with single, impacted, proximal ureteral stones undergoing percutaneous nephrolithotomy (PCNL) and ureteroscopic lithotripsy (URSL). Between January 2005 and January 2006, a total of 53 consecutive patients with solitary, impacted, proximal ureteral stones > 15 mm in diameter who had undergone PCNL or URSL treatments were enrolled in this study. The mean age was 48.5 +/- 11.8 years. PCNL and URSL were performed in 22 and 31 patients. Stone burdens in the PCNL and URSL groups were 232.8 +/- 113.2 mm2 and 150.3 +/- 70.3 mm2, respectively. The efficiency quotient (EQ) for the PCNL and URSL groups was 0.95 and 0.67, respectively. The stone-free rate at the 1 month follow-up was 95.4% in the PCNL group and 58% in the URSL group (p < 0.001). Two patients in the PCNL group had blood loss requiring transfusion. Eight patients had stones showing upward migration during the URSL procedure, and these stones were subsequently treated by extracorporeal shock wave lithotripsy and PCNL. For an impacted, proximal ureteral stone > 15 mm in diameter, PCNL had better stone-free rates and could simultaneously treat coexisting renal stones. However, URSL had the advantages of shorter operative times, shorter postoperative hospital stays, and fewer postoperative complications.