For prevention of pregnancy after coitus, the ineffectiveness of douching is recognized because sperm can be out of reach of douches and spermicides too quickly. The nonsteroidal estrogen diethylstilbestrol (DES) has been used most often. Steroidal estrogens, e.g., ethinyl estradiol and conjugated estrogens, are also effective. Progestogens may also be effective. Hormone administration should begin as soon after coitus as possible but never later than 72 hours. Estrogens are given orally, usually for 5 consecutive days in doses of 50 mg/day. The ethinyl estradiol dose is 5 mg/day; conjugated estrogens, 20-25 mg/day; and estradiol benzoate, 30 mg/day for 5 days has been given by injection. These methods have been approved for emergency use only. Pregnancies have followed in not more than 2.4%. Some studies have reported no failures and others as low as .04%. The estrogen is thought to interfere with implantation of the blastocyst in the endometrium. A copper IUD might prevent pregnancy if inserted within 5 days after coitus. Folk methods, of which most depend on magic, are described. Douching has been used since ancient times with wide range of agents. When diaphragms or spermicides are also used, postcoital douching should not be done within 6 or 7 hours. When postcoital estrogens fail, the resulting pregnancy is ectopic in 10% of cases as compared with .5% of normal pregnancies. A high percentage of ectopic pregnancies also follow IUD or minipill failures. There is no likelihood that DES or other estrogens administered postcoitally will lead to genital cancer in female offspring if the treatment fails. A single case of acute pulmonary edema has been reported. Nausea and vomiting may occur, and menstrual patterns may be altered. Trials have shown that the progestogens d-norgestrel and quingestanol acetate are effective postcoital contraceptives. Combined estrogens and progestogens have been used successfully as postcoital contraceptives. Postcoital insertion of a copper IUD has been tried with apparent success. Further evaluation is recommended. Postcoital methods fill an important gap in fertility control services.