Shortly after the requirement to report venereal diseases to health authorities was lifted, several venereal disease clinics (DAVs) and clinicians specializing in the management of sexually transmitted infections (STIs) spontaneously reported to the Institute for Public Health Surveillance an increase in the number of diagnosed cases of early syphilis among their patients. A reactive epidemiological investigation conducted in close collaboration with the DAVs and clinicians thus confirmed the resurgence of syphilis and identified the main epidemiological characteristics of those affected. This phenomenon, detected in the Paris region, does not appear to be limited to that area.