Extra-corporeal shock wave lithotripsy (ESWL) is clearly an effective treatment for a wide variety of upper urinary tract calculi. The rapid acceptance and adoption of ESWL have been facilitated partly by the fact that this technology is entirely safe and that shock wave treat-ment does not induce severe, acute or chronic side effects.However, there are currently numerous clinical and experimental reports showing that ESWL does obviously cause some severe, acute, side effects (Chaussy et al., 1986; Lingeman et al., 1987; Knap et al., 1987).This study is an attempt to investigate more deeply the effects of ESWL on renal tissue through the selection of one hundred patients with stone size suitable for ESWL, and studying the effect of ESWL through pre-ESWL evaluation and post-ESWL evaluation for a period of 12 months.