The frequency of the urolithiasis in the world according to some cross-sectional studies stays at the level of 3.5-9.6%. In the last 10 years the urolithiasis in many countries shows a tendency for growth. Metabolic syndrome (MS) is a pathologic complex of the symptoms, which includes different metabolic and hormonal disturbances. The frequency of the MS in the population is rather high, and according to scientific data is at the level of 14-39%. Recently it was supposed, that urolithiasis and MS share common entities. More often patients with MS have uric acid stones. It was shown in the scientific investigations, that three pathophysiologic mechanisms lie in the basis of the uric acid stones formation: 1) very low pH of the urine; 2) low diuresis because of low water intake; 3) hyperuricosuria. At that, it is considered that the most important factor is a low pH of the urine (pH≤5.5). Among the causes of the high urine acidity are disturbances in the excretion of the ammonium ions (NH4+) and excessive excretion of the acids (net acid excretion - NAE). Besides uric acid stones MS-patients have also the other types of the stones. More often they have Ca-oxalate stones or mixed stones (uric acid/Ca-oxalate). It is being widely discussed over the role of the hyperinsulinemia and insulin resistance (as a background for MS) in the stone formation, so as over the connection between different components of the MS (such as arterial hypertension, hyperglycemia, hypertriglyceridemia, etc.) and risk factors for the urolithiasis.