Aim. To evaluate the relationship between the salt intake (NaCl) and the clinical and hemodynamic parameters in patients with hypertrophic cardiomyopathy (HCM).Material and methods. Forty four patients with HCM (mean age, 60,4±15,3 years) were examined. Particular attention was paid to intraventricular obstruction and hypovolemic syncope. NaCl consumption was estimated by 24-hour urine sodium test.Results. An inverse correlation was found between syncope and 24-hour natriuresis (r=-0,3, p=0,04). At 24-hour natriuresis <50 mmol/day, syncope was more common (p=0,02): odds ratio (OR), 12,3 (95% confidence interval (CI): 1,3-121,3, p=0,03), as well as <65 mmol/day (p=0,04): OR, 8,3 (95% CI: 1,13-60,3; p=0,04). At higher 24-hour urine sodium values, no reduction in syncope risk was recorded. A correlation was found between low values of left ventricular (LV) stroke volume index (SVI) (<26 ml/m2) and 24-hour urine sodium (<50 mmol/day) (r=0,5, p=0,01). An inverse correlation was observed between LV SVI and syncope at 24-hour natriuresis <50 mmol/day (r=-0,9; p=0,05). An inverse relationship was found between the intraventricular obstruction and 24-hour urine sodium (r=-0,4, p=0,01). The prevalence of obstruction increased as natriuresis decreased: at 120 mmol/day, OR was 4,3 (95% CI: 1,01-18,6, p=0,048), at 110 mmol/day, OR — 4,6 (95% CI: 1,218,1, p=0,03), and at 100 mmol/day, OR — 4,0 (95% CI: 1,1-11,7, p=0,04). An increase in 24-hour urine sodium >130 mmol/day was not followed by a further decrease in obstruction prevalence.Conclusion. To reduce the obstruction risk, the optimal 24-hour urine sodium level is ≥130 mmol/day (NaCl, 7,5 g/day). To reduce the syncope risk, regardless of obstruction presence, the optimal level of 24-hour natriuresis is ≥65 mmol/day (NaCl, 3,8 g/day).