Concrement lithotripsy in the kidney and ureter using extracorporeal shock waves (ESWL) was performed with the aid of a 2nd-generation lithotriptor--Lithostar Siemens. Over a period of 11 months ESWL was applied in 526 patients aged 7 to 80 years, 10 of these were children. 19 patients had bilateral lithiasis so that the treatment was applied to a total of 545 renoureteral units and 698 concrements were disintegrated. In the ureter 34 concrements were disintegrated, the remainder being in the kidney. 12 patients had solitary kidney lithiasis; 62 subjects prior to ESWL, had been operated on the same kidney for lithiasis or on the ipsilateral ureter. Most patients had only local infiltration anaesthesia of the relevant intercostal nerves sometimes supplemented with mild opioid analgesia. Children were operated on in general anaesthesia. More than one ESWL application was needed in 33% cases, 54 disintegrated concrements measured more than 30 mm. Cystine concrements in 2 patients remained unaffected, in 1 woman with apatite lithiasis the disintegration was unsatisfactory. Auxiliary interventions had to be performed in 22% cases, prior to ESWL, and in 13% patients after ESWL, in 1 case following ESWL, open ureteromy was performed. The patient's exposure to radiation is negligibly low, the paramedical personnel is exposed to none. The noise level both for the patient and personnel is within the hygienic limits and is lower than in the case of 1st--generation lithotriptors. The average hospitalization period in patients with unilateral lithiasis lasted 7 days, 8 patients were treated in out-patient departments. When released from the clinic, 39.5% patients had no concrements, the remainder had only minute residual concrements. Three months upon the release, 77.6% patients were found with no demonstrable signs of concrements.(ABSTRACT TRUNCATED AT 250 WORDS)