Earlier and more frequent sexual activity and the significant risk of pregnancy have increased the need for contraception among young adolescent girls. The problem for the physician is to choose a contraceptive method which will not affect future fertility or the psychological and biological maturity of adolescents. Condoms, diaphragms, and spermicides are quite effective if used correctly; they have no deleterious side effects, and they provide protection against sexually transmitted diseases. They appear to be well-adapted to the sporadic sexual activity of adolescents. The efficacy of combined oral contraceptives (OCs) is also high. Side effects depend on the synthetic estrogen component and are dose dependent. Absolute contraindications to OC use in women of any age include thromboembolic disease, cerebral vascular accidents, severe cardiac or hepatic disorders, breast or genital cancer, pregnancy, undiagnosed genital bleeding, and pituitary adenoma. Relative contraindications include hypertension, diabetes, hyperlipidemia, obesity, history of hepatitis, migraines, epilepsy, asthma, renal insufficiency, cystic breast disease, and mammary fibroadenomas. Combined OCs do not seem to interfere with subsequent maturation of the hypothalamopituitary axis. The frequency of ovulatory cycles in adolescents who have discontinued pill use is the same as that in adolescents who have never used pills. However, estrogens accelerate the process of maturation in the bones, so combined OCs should never be prescribed for girls who have not terminated their growth. Minidose OCs containing 30-45 mcg of ethinyl estradiol aggravate the relative hyperestrogenism of adolescents and are associated with menstrual problems, functional ovarian cysts, and breast problems. They should only be prescribed for adolescents with regular sexual activity, no less than 3 years following menarche, with regular ovulatory menstrual cycles and no history of breast disorders. Otherwise, a standard-dose combined pill with 50 mcg EE should be selected. Continuous dose progestin minipills depend on peripheral effects such as modifications in the cervical mucus for their contraceptive effects. They are associated with frequent menstrual problems, functional ovarian cysts, and extrauterine pregnancies. They may be indicated for adolescents with regular sexual activity but with contraindications to combined OCs. Trimonthly injections of medroxyprogesterone acetate have major effects on endocrine metabolism and should be used only for adolescents with severe mental problems. IUD efficacy is high but they may be less well tolerated by adolescents than by older women and the risk of infection may be heightened. They should only be used for adolescents with absolute contraindications to use of hormonal contraceptives who have no history of genital infections.