Even though the urinary stones are rare in children, careful observation and monitoring are necessary because the incidence has been increasing. This study is aimed to document the characteristics of urinary stones in children including the symptoms, diagnosis, with or without urinary tract infection, other urinary tract anomaly and treatment. 45 patients under the age of 15 years with urinary stones hospitalized during Jan. 1986 to Jun. 1996 at Severance Hospital were reviewed retrospectively. Patients' mean age was 6.5 years and sex ratio (male : female) was 5.4:1. The most common symptom was gross hematuria. Stones accompanied with urinary tract infection was 46.7%, and stones associated with urinary tract anomaly was 35.6%. Extracorporeal shock wave lithotripsy, percutaneous nephrolithotorny, hydration and diuretics were the treatment modality used. Urinary stone were found to be a significant cause of urinary tract obstruction in children, requiring prompt diagnosis and treatment. Although KUB, IVP, and ultrasonography were commonly used to make the diagnosis, many cases were detected only by ultrasonographic study.