The possible potential role of several infectious agents in atherosclerosis has been shown. Several infectious agents DNA in atheromatous plaques have been displayed by PCR. In patients with atheromas antibody levels against Hsp65 were higher. Vaccination of mice with recombinant Hsp65 and Hsp65-rich M. tuberculosis resulted in formation of atheromatous plaques. We attempted to detect M. tuberculosis DNA in atherosclerotic plaque samples by PCR. In endarterectomy tissue samples obtained from patients during coronary artery bypass graft surgery DNA was prepared by proteinase-K digestion, phenol/chloroform extraction and ethanol precipitation. After amplification with M.tuberculosis complex IS6110 region specific primers, the products were analyzed on electrophoresis. M. tuberculosis DNA was negative in all tissue samples. More data on etiological studies with mycobacteriaceae will be yield information on atherosclerosis pathogenesis.