AIM To assess concentration of metalloproteinase (MMP) -9 and its inhibitor in blood serum of patients with defects of left cardiac chambers, associated with pressure or volume overload. RESULTS Elevation of MMP-9/TIMP-1 ratio at the account of MMP-9 was characteristic for patients with volume overload while elevation of blood serum level of TIMP-1 was characteristic for patients with pressure overload. MMP-9/TIMP-1 coefficient was directly related to left ventricular myocardial mass index and negatively related to myocardial contractile capacity. In patients with aortic stenosis elevation of TIMP-1 content was associated with lowering of global left ventricular contractility. Concentration of MMP-9 in blood serum and MMP-9/TIMP-1 ratio depended on etiology of valvular heart disease. Values of the given parameters were maximal in patients with mesenchymal dysplasia and sclerodegenerative calcinosis of the aortic valve. CONCLUSION Serum levels of MMP-9 and TIMP-1, as well as MMP-9/TIMP-1 ratio reflect type and severity of hypertrophy of the myocardium and can be looked upon as markers of myocardial remodeling.