PIP: Unintended pregnancy associated with contraceptive failure, not using contraception, or forced intercourse is common in the US. Although emergency postcoital contraception has been available to US health care providers for more than 15 years, few women are aware of its existence. When taken correctly, emergency contraception is effective 95% of the time. Postulated mechanisms of action include prevention of release of the egg, alterations in the egg's protective coating so as to resist sperm penetration, or alterations in the uterine lining to prevent implantation. The emergency contraceptive pill is not meant to be used as a routine form of fertility control and does not prevent the transmission of sexually transmitted diseases. Although the method is safe and reliable, women should be instructed to report any severe abdominal pain, chest pain, severe headache, visual changes, severe extremity pain, and jaundice that follow pill use. Nurses are in an ideal position to answer women's questions about the safety and efficacy of emergency contraception, counsel them on their options, and make referrals for routine gynecologic care and sexually transmitted disease screening. US women can obtain a list of emergency contraception providers in their area by calling the Reproductive Health Technology Project Hot Line (1-800-584-9911).