The presence of human cytomegalovirus (HCMV) nucleic acids was demonstrated in almost all major arteries of HCMV-seropositive patients by polymerase chain reaction. The amount of HCMV nucleic acids present in the arterial wall was calculated to be less than 2 viral genomic equivalents per 2500 human genomic equivalents. No relation was observed between the presence of HCMV nucleic acids in the arterial wall and the existence of atherosclerotic changes. No differences were observed in the number of viral genomic equivalents present at sites with or without atherosclerosis. Apart from a role for HCMV in the pathogenesis of atherosclerosis, the presence of latent HCMV in the arterial tree provides a powerful system to describe the physical state of this latently present virus.