In the Zutphen Study, cholesterol determinations were carried out in 1960 in serum of 829 middle-aged men. Between 1960 and 1985, detailed information was collected on morbidity and mortality in these men. During 25 years of follow-up, 179 men developed myocardial infarctions and 203 developed cancer. During this period, 110 men died of myocardial infarction, 144 of cancer, and 410 of all causes. Survival analysis showed that the serum cholesterol level in 1960 was independently related to the 25-year incidence of myocardial infarction. This long-term relation was mainly due to the strong association between serum cholesterol level and 15-year incidence of myocardial infarction. Similar but less pronounced relations were found between serum cholesterol level and 15- and 25-year mortality from myocardial infarction. Serum cholesterol level was related neither to long-term incidence of and mortality from cancer nor to mortality from all causes.