The relationship between risk factors and cardiovascular disease (CVD) was determined using data from the Nijmegen Cohort study, an 18-year prospective study. In 1977, cardiovascular risk factors were measured in 7092 Caucasian males and females from six general practices: age, smoking, serum cholesterol, blood pressure, body mass index and a family history of CVD were related to subsequent CVD mortality and morbidity. Most patients had more than one risk factor in particular among men. A significant relationship between risk factors and CVD was demonstrated. In men, a relative risk (RR) of 1.8 was found for both high blood pressure and smokers. A positive family history yielded a RR of 1.8. The risk increased gradually with the number of risk factors; 38% of the group with all risk factors suffered a CVD within 18 years. In women, comparable RRs were found but the low absolute risk of CVD should indicate against the treatment of cardiovascular risk factors.