We examined a total of 125 patients, of whom 70 suffered from rheumatoid arthritis (RA). The comparison group was composed of 40 patients diagnosed with osteoarthrosis deformans (OD) and 15 with atherosclerosis of the major arteries of the head (MAH). The control group consisted of 40 subjects randomized by sex and age. Studied were the carotid, vertebral arteries and the cerebral blood flow by means of colour duplex scanning on the unit "Vingmed system, 5, Norway, 2002". Patients with RA as compared with those from the control group showed thickening of the vascular wall of the carotid arteries, especially manifested in patients with seropositive rheumatoid arthritis and in those suffering from RA with systemic manifestations of the disease. The findings obtained by the duplex scanning in patients with RA as compared with those of the control group and OD patients demonstrated an increased number of stenotic lesions of the carotid and vertebral arteries particularly pronounced in seropositive RA and RA with extraarticular manifestations of the disease. Statistically reliable findings were obtained while studying the deformities of the carotid arteries. Comparing the RA groups revealed significant differences: in the group of patients suffering from RA with the systemic manifestations noted was an increased percentage of the kinking along both the common carotid artery (chi(2) = 1.76; NS) and the interpal carotid artery (chi(2) = 8.44; p = 0.01). The findings obtained in the present study strongly suggest that in RA patients there take place alterations in the IMC in the form of a thickening with disordered differentiation of the intima-medial layers and the lesion of the cardiovascular system, which is characterized by an early development of atherosclerosis. The degree of atherosclerotic alterations is associated with the presence of systemic manifestations of RA, high activity of the inflammatory process, and seropositivity by the rheumatoid factor.