Background and methodology In 1999, the Government set the ambitious target of halving the number of under-18 conceptions by 2010. It is now clear that this target will not be met. Much media and policy attention has been paid to teenage mothers, and yet approximately 50% of teenage conceptions end in abortion not motherhood. In London, where the present research was based, the percentage is significantly higher. The research into teenage abortion and repeat abortion, though based in London, generated insights that could potentially help different areas reduce the number of under-18 conceptions ending in abortion. A qualitative research methodology was adopted and a wide range of interviews were conducted with young women, and professionals, in 10 London primary care trusts. Results Our analysis adds to a substantial body of qualitative research that points to the complexity of sexual decision-making for young women. Contraceptive risk-taking was evident as some young women spoke of the difficulties they experienced with user-dependent methods (primarily the condom and the pill) in often unplanned, sexual encounters. They were also generally poorly informed about different contraceptive methods. Misunderstandings about fertility also emerged as an important issue that can lead young women to draw the wrong conclusions if they do not become pregnant following unprotected sex. Conclusions Young people need improved access to, and informed understanding of, the full range of contraceptive methods available to them. In addition, efforts should be made to enable young women to have a better understanding of their own likely fertility.