The so-called classic risk factors of coronary heart disease (CHD) do not explain all its clinical and epidemiological features. Recent evidence suggests that certain infections, among them dental infections, are involved in the pathogenesis of CHD. Case-control studies have revealed an association between dental infections and acute myocardial infarction and chronic coronary heart disease. A large epidemiological survey revealed an association between missing teeth and CHD and a recent 14-year follow-up of 9760 individuals showed that periodontitis is associated with an increased risk of coronary heart disease. Preliminary results suggest that the severity of dental infections correlates with the extent of coronary atheromatosis. Individuals with severe dental infections also have higher level of von Willebrand factor antigen, leukocytes and fibrinogen. Streptococcus sanguis has been shown to aggregate human platelets in vitro. The mechanism behind the association between dental infections and CHD could be the effect of bacteria on the cells taking part in the pathogenesis of atherosclerosis and arterial thrombosis.