Oral contrceptives (OCs), usd by over 30% of reproductive aged women in Belgium, are by far the most widely used contraceptive in that country. The various types of OCs include monophasic, biphasic, and triphasic combinations of an estrogen and a progestin, sequentials containing estrogen only for 7-14 days followed by a progestin through the 21st day; macrodose or microdose progestin only formulations, 3-month injectable progestins, and the morning after pill. Side effects of OCs are mainly due to metabolic effects on coagulation factors, the renin-angiotensin system, glucose tolerance, or the lipid profile. Users of OCs face increased risks of cholelithiases, thrombophlebitis, thromboembolism, cerebrovascular accidents, myocardial infarcts (among smokers over 35 years of age), and hepatic adenomas. The most troubling secondary effect is the excess cardiovascular morbidity and mortality show by contraceptive users, not just those who are obese, hypertensive, or who have histories of vascular pathology, but also those over 40 years of age and smokers. Lenght of use of OCs does not increase vascular risks. Epidemiologic studies demonstrate that vascular risks are reduced in lower dose formulations. Absolute contraindications to OC use include serious cardiovascular problems, severe hepatic pathology, estrogen-dependent tumors, pregnancy and undiagnosed gynecologic problems, and significant hyperlipidemia. Relative contraindications include severe headaches, cholelithiase, previous cholestasis of pregnancy, severe renal disease, fibromyomas, benign breast disease, age over 40 years, smoking, surgery anticipated within 4 weeks, infectious mononucleosis, falciform anemia, and immediate postpartum and lactation. Epilepsy, diabetes, depression, and varicose veins are not strictly speaking contraindications but require additonal surveillance. Lower dose formulations should be prescribed if possible. OC users should be followed up every 6-12 months. Among other steroidal contraceptive methods, sequential OCs and high dose progestin-only formulations are used for short-term treatment of specific conditions. Progestin-only minipills are used when an OC is desired but estrogens are contraindicated. Injectable progestins should be reserved for patients who for cultural or medical reasons can use no other type of contraceptive. Morning-after pills should not be considered a regular form of contraception. If OCs are used in adolescents, a low dose pill is indicated. Low dose OCs may be indicated for diabetics because of the danger of infection with IUDs and the lesser efficacy of barrier methods. If OCs are used in epileptics, they should be regular dosed because of the danger of drug interactions. Only low-dose formulations and progestin-only minipills should be used by women over 40.