Background - Following a resurgence of syphilis in 2000, a surveillance system was established. Analysis of the collected data allows for monitoring trends and describing cases. Methods - The surveillance system relies on voluntary participation by clinicians. The case definition includes primary, secondary, and early latent syphilis. Results - Between 2000 and 2006, 2,306 cases were reported. After a decline in 2005, the number of cases rose again in 2006; it was higher than in previous years, particularly in the Île-de-France and Nord-Pas-de-Calais regions. The majority (83%) of people with syphilis are gay or bisexual men. HIV seropositivity has declined and has stabilized since 2003 at 48%; the proportion of patients with a history of syphilis is increasing. The number of women is increasing each year. Conclusion - The syphilis epidemic remains ongoing in 2006, affecting gay and bisexual men in particular; however, the number of cases among heterosexuals is also increasing. In this context, the significant risk of HIV transmission and the possibility of congenital syphilis underscore the need for syphilis prevention and screening campaigns. (R.A.)