Patients with heterozygous family hypercholesterolemia (HFH) were divided into two groups. Group 1 patients received lovastatin in a daily dose 40-60-80 mg under control of lipids and peripheral blood biochemistry. In 17 patients lovastatin was given as monotherapy, in 15 patients it was combined with plasmapheresis. No hypolipidemic therapy was given to ten patients of group 2. The treatment and follow-up lasted for 4.1 +/- 1.9 years, on the average. A marked hypolipidemic effect was seen in the comorbid therapy. 43% of the patients became resistant to lovastatin, the resistance developed more frequently in monotherapy. The blood fibrinogen fell by 40%, spontaneous and induced platelet aggregation returned to normal, being somewhat higher in subjects resistant to lovastatin therapy. The study shows that hypolipidemic therapy has reduced the risk of IHD fatal complications and progression of non-coronary atherosclerosis in patients of group 1.