The article summarizes the use of laboratory analysis as described in the recently published Norwegian program for diagnosis and treatment of hypercholesterolemia in adults. Serum cholesterol is used both to diagnose hypercholesterolemia and to monitor the effect of treatment. Serum triglycerides should be measured when hypercholesterolemia has been found and dietetic treatment is considered. High density lipoprotein (HDL) cholesterol should be measured when dietetic treatment has not reduced hypercholesterolemia sufficiently and drug treatment is considered. We do not at present recommend measurement of apolipoproteins and factors within coagulation/fibrinolysis, but such measurements might be of importance in the near future. Blood cholesterol exhibits large biological variations, which makes retesting necessary before hypercholesterolemia is diagnosed. Analytical variation is usually less than biological variation, but requires use of quality control materials. This control is equally important for small dry chemistry analyzers as for wet chemistry analyzers.