After three months of beclobrate treatment (100 mg once daily) of 63 patients with primary hyperlipoproteinemia (HLP) significant decrease of total cholesterol concentration was found in type IIa by 12.9%, IIb by 23.7%, IV by 20.8%. LDL cholesterol concentration decreased in type IIa by 15.4%, IIb by 8.3%, in type IV non significant increase of LDL cholesterol by 21.6% was observed. Decrease of initial triglyceride level in type IIa by 36.1%, IIb by 41.2%, in type IV by 56.6% was found. HDL-cholesterol concentration increased in all examined HLP types in IIa by 19.5%, IIb by 19.3%, IV by 14.5%. Also initial apolipoprotein A1 and A2 levels increased in all HLP types examined, namely in type IIa respectively by 21.2% and 12.4%, IIb by 25.1% and 11.0%, in type IV by 23.6% and 34.9%. Serum apolipoprotein B concentration decreased significantly in type IIa by 20.5%, IIb by 28.4%, however in type IV a slight increase of apoprotein B level was observed. Comparison of HLP types response to beclobrate treatment revealed that the HLP types examined are significantly different in change size of LDL cholesterol concentration, triglyceride concentration and apoprotein B concentration after treatment.