Risk factors for myocardial infarction, sudden coronary death, angina pectoris, stroke and total mortality were analysed in a random population sample of men aged 47-55 years at entry, and followed for 11.8 years. Lipid disturbances, tobacco smoking, elevated blood pressure, diabetes mellitus, obesity, low physical leisure-time activity, psychological stress (for non-fatal events) and excessive alcohol consumption (for fatal events) were the main independent risk factors for coronary heart disease. The attributable risk was also calculated. Uncomplicated angina pectoris was related to dyspnoea during exertion, psychological stress, diabetes mellitus and high relative body weight. Stroke was dependent on elevated blood pressure, tobacco smoking and psychological stress. Quantitatively, the most important risk factors for total mortality were low physical activity during leisure time, tobacco smoking and elevated blood pressure. For patients who had suffered myocardial infarction or angina pectoris, elevated serum cholesterol, elevated blood pressure and tobacco smoking were of prognostic importance. Hypertension, together with lipid disturbances and tobacco smoking, was thus found to be a risk factor both for primary and secondary events, and blood pressure control seems of great importance in preventing these cardiovascular events.