We assess the safety and efficacy of rigid ureteroscopy for the treatment of pediatric ureterolithiasis. The records of 33 children with an average age of 7.4 years (range 9 months to 15 years) treated with rigid ureteroscopy between May 1995 and July 2003 were reviewed. In 35 ureteral units use of a rigid 6.9 to 10Fr ureteroscope was planned for treating stones at various levels of the ureter. Stones were located in the upper ureter in 6 cases, middle ureter in 3 and lower ureter in 26. Dilatation of the ureteral orifice was necessary in 11 cases. Stone size varied from 3 to 10 mm (mean 5.3). In 33 patients (94%) all stone fragments were removed successfully. Stones were fragmented with pneumatic lithotripsy in 20 cases and removed by forceps without fragmentation in 13. In 1 child an upper ureteral stone migrated up to the kidney during ureteroscopy but following extracorporeal shock lithotripsy therapy she was rendered stone-free. In another child it was not possible to remove the stone. In a 9-month-old female patient with bilateral stones it was not possible to enter the left ureter because of a tight orifice resistant to balloon dilation. At the end of the procedure a 3 or 4Fr ureteral or a 4.8Fr Double-J (Medical Engineering Corp., New York, New York) stent was left in place for 3 days to 3 weeks in 12 cases. There were no cases of ureteral perforation. Of the patients 31 were followed for 1 to 36 months. No incidence of vesicoureteral reflux was detected in 9 who underwent postoperative cystography. After becoming experienced and meticulously working with finer instruments in adults, rigid ureteroscopy can be a safe and efficient treatment for ureteral stones in every location in children.