Helicobacter pylori infection is probably one of the most widely spread infectious diseases in man and a growing body of knowledge provides evidence in favour of a causal link between this infection and the majority of upper gastrointestinal conditions. For example, we now know that peptic ulcer disease is an infectious disease; if the infection is diagnosed and treated, ulcer can be cured. On the other hand, in recent years, a number of epidemiological studies have focused on the possible relation between ischaemic heart disease and several infectious disorders, such as chronic dental infections, Cytomegalovirus, Coxsackie viruses, Chlamydia and, finally Helicobacter pylori. The results of studies on the association between ischaemic heart disease and Helicobacter pylori have, in particular, often been contradictory, and only some studies adjusted the results for confounding factors, and the adjustment of the results in some cases modified the association. In conclusion, even if coronary atherosclerosis may now be considered as an inflammatory process, according to several histologic and pathophysiologic studies, we cannot, for the moment, be sure that it is an infectious disease.