Launched in 2000 by the French Institute for Public Health Surveillance (INVS) and the National Union of Gay Businesses (SNEG), the Gay Barometer (BG) survey periodically surveys men who have sex with men (MSM) who frequent gay venues about their sexual behaviors. The decline in preventive practices first observed in 2000 has continued to increase in recent years. In 2002, the Gay Barometer (BG) reported an increase in risky behaviors compared to the 2000 survey, and in 2004 the Gay Press survey also showed a considerable increase compared to the 1997 and 2000 editions. This decline in prevention practices has also been observed in other Western European countries. In this context, it was urgent for the INVS to repeat the BG survey in partnership with the SNEG and the Aides Ile-de-France association in the Paris region. The objective was to describe sexual practices that pose a risk for HIV and sexually transmitted infections (STIs) among men who frequent gay meeting places.