Oral contraceptives (OCs) are a highly effective and widely accepted means of avoiding pregnancy, but they also worsen the major atherogenic cardiovascular risk factors to some degree in all women. Some OC users may suffer severe hypertensive episodes or massive hypertriglyceridemia with pancreatitis. Mild or severe adverse effects could eventually have serious consequences beyond the childbearing years. OC use would appear imprudent for women with a history of hypertension, gestational hypertension and a family history of hypertension. Special care is needed with blacks, diabetics and women with renal disease. OCs may also affect blood clotting, fibrinolysis and platelet adhesiveness. Also, histochemical and anatomical changes in blood vessels have been noted. Both may precipitate thromboembolic events while the OC user is still at the childbearing age and may also contribute to accelerated atherogenesis in subsequent years. There is a need for more specific guidelines for monitoring women on OCs for a worsening of their cardiovascular risk profile and changes in blood coagulation. Indications and contraindications for OC use in relation to the hazard of thromboembolic sequelae need to be more explicitly defined