Clinical experience with 2738 patients treated by extracorporeal shock wave lithotripsy between March 1985 and December 1988 is reported. All treatments were performed with the Dornier HM-3 lithotriptor. 34% of the patients needed auxiliary measures, consisting primarily of urological manipulation to improve urinary drainage or for better localization and/or focussing of the stones. Severe complications were rare; urosepticemia occurred in 0.3%, 2 patients had to undergo nephrectomy because of abscessing pyelonephritis, and there was one death due to recurrent pulmonary embolism in a patient with polycythemia vera. ESWL was used for stones in the entire upper urinary tract. The stone free rate for pelvic calculi smaller than 2 cm was 79% three months after treatment; a further 16% showed desintegrated material smaller than 5 mm, augmenting the success rate to 95%. The success rate dropped to 74% for very large renal stones of more than 4 cm. A stone free rate of 84-96% was ascertained for ureteral calculi 3 months after ESWL. Absolute contraindications for ESWL are acute pyelonephritis, coagulation disorders and pregnancy. The patients must tolerate anesthesia, as most treatments with this lithotriptor must be carried out under peridural or general anesthesia and only in a few exceptional cases is treatment in sedoanalgesia possible. ESWL is now generally accepted in view of its negligible invasiveness, low morbidity and the high success rate. Modern treatment of urinary calculi is inconceivable without considering ESWL.