Fifty children presenting with ureteral calculi over a twenty-year period were studied retrospectively. There were 35 boys and 15 girls, with a mean age of five and a half years. Nineteen patients had a urinary tract anomaly: 11 had an obstructed megaureter, and 8 had previously undergone urinary tract surgery. Forty-four children had infection stones and the remaining 6 oxalate calculi. Infected urine was found in 35; the infecting organism was a Proteus species in 23. Metabolic abnormalities were detected in 2 children. Operative removal of the stones was done in 39 patients, and in the remaining 11 patients the stones passed spontaneously. There were 6 recurrences, all within four years of initial presentation.