Atherosclerotic cardiovascular disease is generally accepted to be the result of metabolic disturbances. However, recent studies have suggested an infectious agent, especially Chlamydia pneumoniae or cytomegalovirus, to be involved in the pathogenesis of atherosclerosis. Atherosclerotic plaque specimens obtained from patients with coronary disease either by balloon dilatation catheter (13 cases) or atherectomy (16 patients) were examined for the presence of C. pneumoniae and cytomegalovirus. Using two primer pairs for C. pneumoniae, two primer pairs for the identification of unknown bacteria and primer pairs for the detection of immediate early gene E2 and the late genomic region of cytomegalovirus, we were unable to detect the suspected agents. The absence of C. pneumoniae, other bacteria and CMV in coronary atheromas is against the hypothesis of a pathogenetic role of these agents in coronary atheroma formation in the patients studied.