Eighty-two children with renal and ureteral stones were treated with the Siemens Lithostar Plus. Of these, 43 (52%) had renal pelvic stones, 9(11%) had both renal pelvic and caliceal stones, 13 (16%) had solitary caliceal stones, 6 (7%) had multiple caliceal stones, 3 (4%) had staghorn stones, 2 (2%) had upper ureteral stones, and 6 (7%) had lower ureteral stones. All children were treated on an outpatient basis, and 15 (18%) were stented prophylactically before lithotripsy. Dissociative anesthesia with ketamine was needed in 75 (91%) of the patients. The maximal shock wave number delivered at a single session was limited to 4000, and shock wave intensity was limited to 17.8 kV. After 3 months, 51 of the children (62%) were stone free and 27 (33%) had residual fragments no larger than 0.4 cm in diameter. Retreatments were needed in 28 of the cases (34%). No major complications were seen in these children. © 1992, Mary Ann Liebert, Inc. All rights reserved.