Chlamydia pneumoniae causes respiratory tract infections, and it is transmitted by air and fomites. It is probably more frequent than it is described, due to asymptomatic or mild symptomatic patients. They respond to macrolides, tetracyclines and quinolones, though patients may recover slowly. An increase of the incidence of pneumonia, caused by Chlamydia pneumoniae, is shown in recent multicenter surveys, being even more frequent than Streptococcus pneumoniae and Mycoplasma pneumoniae. Recently it has been demonstrated an association between coronary artery disease and atherosclerosis with Chlamydia pneumoniae infection. Special attention must be paid to the cardiovascular complications of Chlamydia pneumoniae. We describe six clinical cases of Chlamydia pneumoniae pneumonia in which two of them suffered from ischemic artery disease as a complication of the infection.