The section for preventive cardiology within the Danish Society for Cardiology has established a lipid group with representatives from The Danish Society for Clinical Chemistry, The Danish Society for Internal Medicine, The Danish Society for Cardiology, The Danish Society of Hypertension, The Danish College of General Practitioners, and The Danish Paediatric Society. The lipid group has elaborated recommendations for clinical chemical departments regarding lipid and lipoprotein analyses. The group suggests that doctors ordering lipid and lipoprotein analyses are offered the following: S-Cholesterol (total), substance conc., (fPt)S-Triglycerides, substance conc., S-HDL-cholesterol, substance conc., and (fPt)S-LDL-cholesterol, substance conc. (calculated). It is recommended that the biological variation be minimized by sampling in a sitting position after a 15 minutes' rest and by basing the clinical decision on a minimum of 2-3 determinations with an interval of about one month. The analytical variations should be reduced to below 3% (calculated as the variation coefficient), and it is recommended that laboratories participate in external quality control systems at least four times annually by reporting at least two human reference materials with different concentrations. As the use of reference intervals dependent on age and sex, based on random samplings of the background population, are less informative, it is recommended to refer to cutoff values for the clinical decision. The following cutoff values are recommended: S-Cholesterol (total), substance conc.: 6 mmol/l, (fPt)S-Triglycerides, substance conc.; 2.5 mmol/l, S-HDL-cholesterol, substance conc.: 0.9 mmol/l (fPt)-LDL-cholesterol, substance conc. (calculated): 4.5 mmol/l.(ABSTRACT TRUNCATED AT 250 WORDS)