The authors review the epidemiological evidence linking causally the level of blood cholesterol to coronary heart disease. The evidence is based both on analytical and experimental epidemiology. They review also the two strategies of prevention: the strategy of screening for the detection of "high risk" subjects and the "population" or mass approach. The distribution of blood cholesterol in Belgium according to the Belgian Interuniversity Research on Nutrition and Health (BIRNH) data is presented. Finally, blood cholesterol is placed within a multifactorial prevention perspective using the Framingham equations. The multifactorial approach is now based on different instruments among which the graphs published by the European Society of Cardiology which are "user friendly".