After 20 years of oral contraceptive (OC) use, epidemiological data and scientific research have led to the now accepted evidence that the most important effect produced by these drugs on humans, other than the prevention of unwanted pregnancy, is an increase in the risk of cardiovascular disease. Because the incidence of cardiovascular disease is also related to disturbances of the lipoprotein metabolism, it appears to be opportune to analyse the different aspects of the interaction between female hormones and lipoprotein (LP) metab- olism. SERUM LIPOPROTEINS: METABOLISM In the serum, lipids (cholesterol (C), triglycerides (TG), and phospho- lipids) are associated with peptides called apoproteins: apoproteins A-I, A-11, B, C, etc. The chylomicrons and the very low density lipoproteins (VLDL) are rich in TG and contain the Apo B-48; the low density lipoproteins (LDL) are rich inC and contain the Apo B- 100; and the high density lipoproteins (HDL) are rich in proteins (Apo A-I, Apo A-Il) and phospholipids.