The efficacy and safety of lifibrol, a novel cholesterol-lowering drug, was investigated in a double-blind clinical study in 168 patients with primary hypercholesterolaemia. Placebo and four lifibrol dose groups (150, 300, 450 and 600 mg/day) were tested over a period of 4 weeks. The mean LDL-cholesterol changes were 5.7%, −11.1%, −27.7%, −34.5% and −35.0%, respectively, after 4 weeks of treatment. No major changes in HDL-cholesterol were seen after this period. With the present study design, a decrease in triglycerides (−28%) was significant in the highest dosage group only. Additionally, it was shown that further independent risk factors for coronary heart disease were favourably influenced. Fibrinogen decreased in all dosage groups with a maximal mean value of 18% and a tendency toward reduction in lipoprotein (a) was observed in patients with high baseline levels (>30 mg·dl−1). Lifibrol was generally well tolerated in all dosage groups and no serious adverse events were reported. Laboratory parameters did not show any clinically relevant alterations.