Matrix metalloproteinases (MMPs) are involved in the remodeling of the extracellular matrix (ECM) in the arterial wall during atherogenesis. Collagens are the most abundant proteins in the ECM. MMP-8 is expressed by cells associated with the development of the atherosclerotic plaque. It cleaves collagen type I three times more potently than two other interstitial collagenases MMP-1 and MMP-13. The aim of this study was to investigate whether plasma MMP-8 values are associated with occurrence of carotid plaque (CP) and possible correlations with clinical and biochemical parameters in carotid atherosclerosis (CA) patients. Total plasma MMP-8 levels were quantified by ELISA in 63 patients with ultrasonographic evidence of CP presence and 12 controls. Plasma MMP-8 values were significantly higher in patients with CA compared with controls (median 23.36 ng/ml vs. 13.02 ng/ml, P<0.001) but they did not differ significantly according to gender, smoking and hypertensive status, associated diseases, and use of statins. Statistically significant positive correlations were observed between MMP-8 plasma values and C reactive protein (r=0.41, P=0.001), urea (r=0.50, P<0.001), aspartate transaminase (r=0.48, P=0.001), and creatinine levels (r=0.38, P=0.006). These results suggest association of MMP-8 plasma levels with occurrence of CP and correlation with certain biochemical markers.