This report summarises the evidence presented to a technical consultation on the safety of N-9 and its effectiveness for protection against pregnancy, sexually transmitted infections and HIV, organized by the World Health Organization Department of Reproductive Health and Research with CONRAD in October 2001. Key conclusions from the meeting include: 1. Although Nonoxynol-9 has been shown to increase the risk of HIV infection when used frequently by women at high risk of infection, it remains a contraceptive option for women at low risk. 2. Nonoxynol-9 offers no protection against sexually transmitted infections such as gonorrhoea or chlamydia. 3. There is no evidence that condoms lubricated with nonoxynol-9 are any more effective in preventing pregnancy or infection than condoms lubricated with silicone, and such condoms should no longer be promoted. However, it is better to use a nonoxynol-9 lubricated condom than no condom at all. 4. Nonoxynol-9 should not be used rectally.