This paper presents a review on cardiovascular diseases which can be caused by chlamydial infection with the emphasis in the recent development in association between Chlamydia pneumoniae and cardiovascular disease. The review includes seroepidemiologic observations; the discovery of C. pneumoniae in atheromatous plaques; in vivo studies using animal models indicating that C. pneumoniae is a co-risk factor of hyperlipidemia for atherosclerosis; in vitro studies demonstrating putative mechanisms by which C. pneumoniae could contribute to the immunopathology of atherosclerosis; and early promising antibiotic intervention studies.