The authors analyse the effects of ESWL on renal function in 180 patients with nephrolithiasis. Renal performance was judged by the level of enzymes. Pharmacological defense of the kidney was made with isradipine and lipostabil given for 12 weeks before lithotripsy and 4 weeks after it. Isradipine proved a good corrector of renal function after lithotripsy as it decreased enzymuria, promoted normalization of the activity of alkaline phosphatase, gamma-glutamyl transferase, alpha-glucosidase and lactate dehydrogenase to the end of the first postoperative month. This indicates quicker recovery of renal parenchyma after ESWL. Lipostabil also improved enzymic indices. Its moderate protective action on renal parenchyma normalized levels of some enzymes one month after ESWL.