Emergency contraception (EC) consists of either 1.5 mg of levonorgestrel (LNG) in one or two doses, or a combination of LNG with ethinylestradiol, administered for up to 5 days after unprotected intercourse. Clinical studies indicate that LNG alone is more effective and has less side effects. Its effectiveness decreases the longer after coitus it is taken. EC is indicated when there is non-compliance or accidents with the use of regular methods of contraception, or when women have had voluntary or imposed unprotected intercourse. The ethics of providing EC has been questioned by some, arguing that it acts by preventing implantation. Scientific evidence does not support this concept, but shows that EC acts mostly before fertilization. Placing obstacles to the access of EC is unethical as it transgresses the ethical principles of autonomy, non-maleficence beneficence and justice. Far from inducing abortions, EC reduces unwanted pregnancies and prevents abortion. (C) 2003 International Federation of Gynecology and Obstetrics. Published by Elsevier Science Ireland Ltd. All rights reserved.823297305