Ischemic heart disease (IHD) is the leading cause of mortality, disability and posting from a ship among seamen. As shown by analysis of case records of 124 seamen who died suddenly of myocardial infarction, IHD lethality on board the ship is much higher than on land. The greatest number of myocardial infarctions and IHD deaths occur on sailing month 3 and 4, within month 1 after returning home. Specific features of myocardial infarction in seamen are the following: absence of typical history, high incidence of painless forms and postmortem diagnosis, rare hospitalization, relationship with low exercise tolerance and inability to reach submaximal heart rate at bicycle exercise. Coronaroangiography performed after myocardial infarction detected stenosing atherosclerosis of the coronary arteries in 95% of cases.