The aim of the study was to examine the relationship between plasma matrix metalloproteinase9 and tissue inhibitor of metalloproteinase type 1 with degree of target organs damage in essential hypertension (EH). A total of 70 patients with EH (37 men, 33 women) aged 41–65 years old, mean age (54.0±2.7) years, were observed, including 33 patients with EH stage II and 37 poststroke patients with EH stage III. The control group consisted of 18 healthy normotensive men, mean age (50.0±4.2) years. Levels of metalloproteinase9 and tissue inhibitor of metalloproteinase type 1 in plasma were determined by ELISA. We observed the evidence of the relationship between the plasma content of markers of collagen degradation and the stage of EH: stage II marked increase in tissue inhibitor of metalloproteinase9 and at stage III – increasing concentrations of both matrix metalloproteinase9 and its tissue inhibitor. Activation of matrix metalloproteinase9 and its tissue inhibitor type 1 was closely correlated with the degree of target organs damage in EH.