The objectives of this cross-sectional study presented as the first stage of a cohort follow-up pharmacoepidemiological study of lipid modulators, are to determine the extent and pattern of use of antihyperlipidemics and concomitant drugs and to compare antihyperlipidemic subgroups. The study population are the 17,244 respondents to the 1991 questionnaire in which questions on drug utilization were asked for the first time. It comprises 40.5% of the men and 32% of the women of the population originally targeted in 1989, i.e. the entire workforce of a national company within an age range of 35-45 years for men and 35-50 years for women. Self-reported health events and drug use over the previous year were measured. Overall 1 year prevalence of use of lipid lowering drugs was 7.7% (9.5% in men and 2.7% in women). Most antihyperlipidemics were fibrates (n = 878), with fenofibrate ranking above ciprofibrate, as opposed to HMG-CoA reductase inhibitors (n = 436), principally simvastatin. Only 60% of antihyperlipidemic drug users were following a prescribed lipid-lowering diet; over half were taking other drugs concomitantly, most often b-blockers. The simvastatin group differs from the fibrate group by an excess of prevalent thyroid disease. The link between simvastatin and thyroid disease may be indication-related. In conclusion, the relevant features of this study are the extensive use of antihyperlipidemics, frequently, without concomitant diet, and the marked preference for antihyperlipidemics for which long term safety is unknown. Extent of use and choices of antihyperlipidemics are corroborated by estimations in the general middle-aged population.