Background and Objective: Since 1980, the first extracorporeal shock-wave lithotripsy (SWL) was introduced which brought a revolution in the treatment of urinary tract stones. Some of the effects and side effects of this method is still unknown. This study aimed to investigate the changes in vascular resistance index (RI) in ipsilateral and contralateral kidney, as well as its relations to time that these changes was carried out. Method: The RI of the interlobar renal arteries was measured for the regions near the calculi, far from it and contralateral kidney, before, one hour after, and 2 week after SWL. Changes in the RI values and their relation with sex and age were evaluated and analyzed by SPSS. Results: The mean age of the patients was 46.5 and they were 56.7% men and 43.3% women. The mean calculus size was 11.8 mm. The RI near and remote from the calculus increased one hour after SWL (p=0.003), but returned to the pre-SWL values 2 week later. The RI values of contralateral kidney did not change significantly. Conclusion: This study suggest that SWL of the kidney calculi changes the RI only in ipsilateral kidney which is immediate, transient, and after 2 weeks return to pre-SWL value.