Association of inflammation with atherosclerosis has been known for many years. Some organisms: Chlamydia pneumoniae, Helicobacter pylori, Cytomegalovirus, Herpesvirus were considered as possible infectious factors responsible for coronary artery disease development. Several studies reported strong association between chronic Chlamydia pneumoniae infection and atherosclerosis. In this review we presented clinical evidence for and against the hypothetical association between coronary arterial disease and Chlamydia pneumoniae.