Abdominal Aortic Aneurysm (AAA) is multifactorial disease with unknown ethiology. Among the theories on the pathogenesis of AAA are some ge. netic factors, infections, disorders in connective tissue (collagenosis), arteriosclerosis, inflammation, incorrect immune response (autoimmunity). It was discovered that crucial for AAA development is intense inflammatory reaction combined with high proteolytic activity. Recent evidence confirmed the association between osteopontin (OPN) and osteoprotegerin (OPG) levels and cardiovascular diseases and arterio. sclerosis. The aim of this work was assessment of plasma levels of OPN and OPG in the group of the patients with AAA and correlation of results with clinical parameters, "classical" risk factors for development of AAA, arteriosclerosis and morbidity. The reference group consist of the patients with Leriche Syndrome (LS). The OPG level was assessed in plasma and OPN levels were assessed in plasma and urine. Plasma OPG levels were higher in AAA group than in LS group (difference not statistically significant, p = 0.0549). It was statistically significant positive correlation between plasma OPN levels and CRP levels in the groups of AAA and LS patients. It was not any association between plasma OPG and OPN levels and abdominal aortic diameter. Plasma OPG levels correlated positively with the existence of coronary artery disease in AAA patients. Insignificant, but higher levels of this protein were found also in a group of AAA patient with myocardial infarction. In LS group we found statistically significant positive association between plasma OPG levels and patient with stroke. However, in AAA patients with incidence of stroke, we found higher plasma levels of OPN. Interestingly, there was not any association between OPN levels in the urine and clinical parameters, risk factors and morbidity, including kidney diseases. inflammatory role of OPN and depicts better reflection of inflammatory reaction of OPN than OPG in both group of patients. Plasma OPG levels in AAA patients are more associated with coronary artery disease than with peripheral artery disease, what is characteristic for LS patients. Lack of association of urine OPN levels with above mentioned parameters suggest minor importance of this urine protein in clinical condition evaluation of patients with AAA and advanced arteriosclerosis.