The concept that it is possible to prevent a pregnancy after coitus is not new, but has gained prominence over the last 10-15 years. It provides a second chance to women who do not want to get pregnant and who, voluntarily or not, have had unprotected intercourse. Emergency contraception has been under strong attack by the Catholic church and anti-choice organisations in Latin America, who claim that the interference with implantation of the fertilised ovum is equivalent to an early abortion. The accumulation of evidence, however, is that the mechanism of action of emergency contraception is to prevent ovulation and that it does not interfere with implantation. This has been ignored by the anti-choice movement. The pattern of opposition to emergency contraception has been the same all over the Latin America region. The medical establishment and civil society, including the International Consortium for Emergency Contraception, have played a key role in defending access to emergency contraception throughout the region. A positive consequence of the public opposition of the Catholic church is that the concept and the method have become better known, and emergency contraception has become widely used. The cases of Peru, Brazil and Chile are described as examples. © 2007 Reproductive Health Matters.