Controversial opinions exist about the possible mechanisms throughout emergency contraception prevents pregnancy. Recently, the International Federation of Gynaecology and Obstetrics and the International Consortium for Emergency Contraception released a Joint Statement declaring that 'inhibition or delay of ovulation should be their primary and possibly only mechanism of action'. They still added that 'Review of the evidence suggests that LNG-ECPs cannot prevent implantation'. Concerning levonorgestrel-only emergency contraceptive pills effects on ovulation, the Statement based on seven reference papers which considered a total of only 142 patients, divided into still different subgroups. Basing on their same references we got quite different conclusions.