Introduction. Extracorporeal Shock Wave Lithotripsy (ESWL) in nowadays is considered a successful method for treatment for kidney stones less than 2 cm and ureteral stones less than 1,5 cm. We analyzed how Hounsfield values density can influence on stone free rate after ESWL. Material and methods. Were analyzed retrospectively 224 patients who had diagnoses of urinary stones (kidney and ureter) and underwent ESWL. Urinary tomography of patients was processed and classified into 4 groups by Hounsfield units (Group 1, < 299 HU; Group 2, 300-599 HU; Group 3, 600899 HU; Group 4, 900-1199HU) and 2 groups by stone size (Group A; < 1 cm, Group B; > 1 cm). Results. Were analyzed in concordance with stone free rate after 3 sessions of ESWL. In Hounsfield unit Group 1 stone diameter was 6.5±3.5 mm, number of shocks was 4000 and number of treatments was 1.2±0.6. Group 2 stone diameter was 10.6±3.1 mm, shock amount was 1.9±0.9. Group 3, stone diameter was 14.7±2.0 mm, and number of treatments sessions was 2.1±1.2. Group 4, stone diameter was 16.7±2.0 mm, and number of treatments sessions was 3.1±1.1. Conclusions. The evaluation of Hounsfield density on computer tomography of urinary stones can be significant factor to stratify the correct indication for ESWL treatment, increase de stone free rate and significant minimalize the development of major complications and unsuccessful procedure.