A 20 year follow up of 1330 patients in the Medical Research Council trial of short term anticoagulant treatment in myocardial infarction showed no long term benefits; but it provided interesting data on the outcome in such patients. Sixteen per cent of the patients were alive 20 years later. The excess mortality rate in trial participants over that expected for England and Wales as a whole declined rapidly after the early months, but some excess persisted throughout the follow up. Three quarters of all the deaths were from coronary heart disease; 70% of these coronary deaths occurred after the patients had left hospital. This finding emphasises the importance of secondary prevention.