The reports on the effectiveness of blood lipid lowering in the primary prevention of ischaemic heart disease have promoted the development of statements and strategies for decreasing plasma cholesterol levels. As the risk of ischaemic heart disease gradually increases with the serum cholesterol level, a shift of the whole cholesterol distribution curve towards lower cholesterol values not exceeding 5.2 mmol/l is found to be desirable. The population survey conducted in the cantons of Vaud and Fribourg, as part of the MONICA-project, has yielded the data about the distribution of serum total and HDL-cholesterol for a representative sample of the population. 34% of men and 30% of women aged 25 to 74 have a blood cholesterol value exceeding 6.7 mmol/l, the percentage of people with high cholesterol levels increasing with age, especially in women. HDL-cholesterol levels, higher in women than in men, remain fairly constant according to the particular age group concerned. On application of the norms proposed by the US Consensus Conference on blood cholesterol, one finds that 32% of women and 37% of men have to be considered as 'high risk' and 18% of both sexes at 'moderate risk' concerning the development of coronary heart disease. The consequences of the application of such norms in Switzerland, as well as the current cholesterol values of the Swiss population as compared to those obtained earlier on in Switzerland and the USA have to be considered on a large scale in order to draw up a global strategy for health promotion and the prevention of cardiovascular disease.