Percutaneous removal of renal and ureteral stones was attempted in 19 cases through an operatively established nephrostomy tract and in 181 cases after primary percutaneous puncture. In the latter group failure of the technique or residual stones required surgical intervention in 15 cases. The residual stone rate was 9/19 and 13/168. The most frequently applied technique of stone removal was by ultrasound disintegration. Of 12 complications 11 were managed conservatively. A "one-step" procedure performed in the last 105 patients resulted in immediate success in 76. Secondary sessions were necessary in 29 patients. Depending on the number of sessions necessary for complete stone removal, the hospitalization time averaged 7 to 12 days.