We followed 270 pediatric stone patients during a 27-year period to determine the recurrence rate of stone disease. Stone disease recurred in 42 patients (16 per cent). When these patients were categorized according to etiology of the stone disease the recurrence rates were infection 14 per cent, idiopathic 14 per cent, anatomical 27 per cent and metabolic 30 per cent. The most prolonged interval to stone recurrence in each category ranged from 7 to 13 years and, thus, long-term followup of pediatric stone patients seems to be important.