We have examined 2 group of patients, overall 137 patients, with the age range 21-74 years, 76 female and 61 male patients. Urate stones were present in 49 patients, calcium oxalate (CaOx) and mixed with prevalence of CaOx in 88 patients. Recurrent urolithiasis was diagnosed in 135 patients. Long-term surveillance (2-15 years) was the case in 93 patients. The following investigations were carried out in patients: anamnesis, urinalysis, serum and urine biochemical panel (14 parameters), analysis of the stone composition. It was determined, that in urate urolithiasis osmolarity of the urine could be a prognostic criteria for the uric acid and sodium urate crystalluria outbreak. The high risk of precipitation is present in case of hyperuricemia and hyperuricuria with the osmolarity approaching 700 mosm/l (716±16 mosm/l). In the CaOx form of the urolithiasis hyperuricemia contribute to the emergence of the calcium oxalate crystals in urine. Concentration of uric acid in serum at the level 0.411±0.038 mmol/l in case of uricemia and uricuria could be used as the prognostic criterion for oxalate crystalluria. High effective agent for the treatment and prophylaxis of uric acid and oxalate crystalluria is blemaren.