Anonymous and free HIV testing clinics (CDAG), thanks to their accessibility and widespread distribution throughout France, provide an easy way to get tested for HIV/AIDS. Epidemiological surveillance of anonymous and free HIV testing is based on the collection of annual activity data by the CDAGs—some of which are located in prisons—and a descriptive cross-sectional survey conducted in 2004 among 5,330 individuals who sought testing. In 2006, the CDAGs served approximately 357,000 people and performed 305,325 HIV serology tests. Of these, 3.9 per thousand tested positive. Half of the clients were under 25 years of age. CDAG branches in prisons have highly varied activity levels and cannot, on their own, provide a comprehensive overview of screening activity within the prison system. The Île-de-France region (particularly Paris) and the French departments in the Americas (DFA) are the regions where CDAG activity is highest and where the most positive test results are found. The consultants’ findings showed that the most affected populations—people from sub-Saharan Africa and men who have sex with men—increased their visits to CDAGs between 2000 and 2004. Outside the prison system, these findings confirm the rationale for these clinics: to integrate screening into a prevention strategy, particularly targeting young people, and to screen among the populations most likely to be infected. Their activities align with the specific challenges of HIV infection in the DFA and in the Île-de-France region. (R.A.)