Drug treatment of hyperlipidaemia should be founded on scientific evidence. A hearing was arranged to arrive at practical measures based on reported clinical trials. Several studies during recent years have shown regression of coronary atheromatosis, and some people would say the effect is striking. Studies using clinical endpoints, like morbidity and mortality, have not yielded equally convincing results, but it should be noted that the results of studies with more than 10% reduction in total serum cholesterol levels are not yet available. So far, the trials have been too small to judge effects on total mortality. It is uncertain whether the treatment actually has untoward effects on the incidence of violent deaths and neoplasms. An upper limit for drug treatment of about 8 mmol/l was proposed during the hearing. The limit can be lowered to 7 if established coronary disease is present. For women without coronary disease the limit should be higher than that for men. All in all, this implies an increase in the total number of individuals treated compared with present practice. It was agreed that at present, high risk individuals are undertreated. The new levels have been set partly on the basis of economic considerations.