It is assumed that various infectious agents play direct or indirect roles in the pathogenesis of atherosclerosis which is accepted as a chronic inflammatory phenomenon. However, the data obtained from different studies are contradictory. The aim of this study was to investigate the roles of herpes virus group [Herpes simplex virus (HSV), Epstein-Barr virus (EBV), Cytomegalovirus (CMV)] and hepatitis A virus (HAV) which are debated in terms of their impact in the pathogenesis of coronary arterial diseases. For this purpose, atherome plaque samples collected from 28 patients (23 were male; age range: 43-74 years) with atherosclerotic heart disease and vein samples from 22 control patients (19 were male; age range: 37-85 years) who had vascular diseases other than atherosclerosis, were investigated by means of the presence of nucleic acids of the above mentioned viruses by real-time polymerase chain reaction (PCR). Besides, classical cardiovascular risk factors (hypertension, hyperlipidemia, hypercholestrolemia, diabetes mellitus, smoking habits, gender, age and familial background) were questioned in both patient and control groups. As a result, no positivity were detected for nucleic acids of HSV type 1 and 2, EBV and HAV, whereas CMV-DNA was found positive in three of 28 (10.7%) atheromateous plaques (viral loads were 21, 188 and 288 copies/mg). Amongst 22 vascular samples from controls, two (9.1%) yielded positive results for EBV-DNA (viral loads were 5 and 10 copies/mg), while the other samples were found negative for nucleic acids of HSV type 1 and 2, CMV and HAV. The evaluation of the known risk factors for atherosclerosis revealed that, the difference between the presence of hypertension and hyperlipidemia which are the major risk factors, was statistically important (p < 0.05) in patient group (64% and 50%, respectively) and control group (32% and 23%, respectively). In conclusion, the hypothesis concerning the possible relationship between these viral agents and the progression of atherosclerosis, have not been supported by our data which are similar to the results obtained from various other studies. Actually, further studies are needed to clarify such direct or indirect roles of infectious agents in the pathogenesis of coronary arterial diseases.