The aim of our study is to determine the efficacy and safety of extracorporeal shock wave lithotripsy (ESWL) as a method of treatment of nephrolithiasis in childhood. Between 1986 and 1994, 50 children with renal calculi were treated by ESWL in our department. The age of the children ranged from 8 months to 14 years. Thirty-three of them were boys and 17 girls. The stone location was in the renal pelvis in 38 cases, in the upper renal calyx in 4 cases, in the lower calyx in 2, while 6 children had staghorn calculi. The stone size ranged between 3 and 39 mm. All treatments were performed with Dornier HM4 except 12 children, all older than 10 years, who underwent ESWL with Dornier HM3. All ESWL procedures took place under general anesthesia or sedation with ketamine. The number of shock waves varied between 400 and 2,000 per treatment and the standard maximum generator voltage was 18 kV. The overall stone clearance rate at 1 month was 66%. Fourteen children with large residual fragments underwent a second ESWL procedure 3 months later. With a mean follow-up of 33 months, 41 children (82%) are stone-free. Ten children developed urinary tract infection and 5 Steinstrasse. Twelve children had a pre- and post-ESWL DMSA scan and no permanent impairment of renal function was observed. We conclude that ESWL is the treatment of choice for urinary tract lithiasis in childhood. It is a low-risk method, without serious complications, which yields as high a success rate in children as in adults. We believe that as the stone fragmentation and clearance is much higher in children that in adults, the method must be the initial approach and may be the monotherapy even in staghorn or complex stones.