Seven hundred and ninety-four males under 60 years who survived a first episode of unstable angina or myocardial infarction by 28 days were admitted to St. Vincent’s Hospital between 1965 and 1981 inclusive. They were followed for at least 4 years: 1-, 2-and 4-year mortality during the follow-up period did not alter significantly during the 17 years. Significant changes did take place over time in the severity of the coronary attacks and in the risk profile of the patients. A greater number of complicated infarcts occurred in the later years and there were fewer smokers and more hypertensives. There was a significant increase over time in the number of initial cigarette smokers who stopped after the coronary attack. Changing methodology made secular changes in cholesterol levels difficult to interpret.