Principally the formation of urinary calculi in children is not very different from that of grown-ups. For children some factors, however, are of special relevance namely recurrent urinary tract infections and malformations in the area of the urinary tract. In western countries nowadays the incidence rate of urinary stones in children is 3-5% of all patients suffering from this disease, in the underdeveloped countries we have rates of about 30%. A clear sex preference in children wasn't found, the age distribution shows that for half of the children suffering from calculi, diagnosis has been made until they've reached school age. Stone localisation is shifting towards the upper urinary tract, in the past we had mainly urinary bladder stones. Concrements containing oxalate are being found more often today. For children we have a high proportion of mixed concrements. The rate of recurrence for children is 15-25%. Diagnostically we have to search out especially for malformations respectively obstructions of the urine flow, disturbances in metabolism in consideration of metaphylaxis possibilities, however, must not be taken out of account either. Promotory and inhibitory factors of stone formation are presented and their significance is explained by means of selected cases of our own patients. Modern techniques of operative resp. instrumental removal of urinary calculi are presented, especially the relevance of modern strategies as e.g. the extracorporal shock wave lithotripsy, percutaneous litholapaxy and ureterorenoscopy are discussed. Adequate metaphylaxis (general, dietetic, medicamentous) can lower the rate of recurrence of stone formation. This is only possible, however, on condition of a consequent diagnosis to find possible causes of stone formation to be able to choose the right measures of metaphylaxis.