One year after the implementation, in early 2003, of mandatory reporting of HIV infection diagnoses, the number of new HIV diagnoses is estimated at approximately 6,000 in 2003. This figure takes into account underreporting of HIV infections, estimated at 35%. It is important to raise awareness among healthcare professionals once again to reduce this underreporting. Overall, HIV testing activity is significant in France: the number of tests per capita (79 tests per 1,000 inhabitants in 2003) is higher than in most neighboring European countries. The number of HIV serology tests performed during anonymous and free screening consultations is increasing, but the proportion of positive serology results per 1,000 tests (5.1% in 2003) remains stable. Data from HIV and AIDS surveillance highlight the continued spread of infection among gay men, who accounted for 21% of new HIV diagnoses in 2003–2004, and of whom one in two became infected within the six months preceding their diagnosis. The proportion of women among those affected by HIV infection is increasing: in 2003, it reached 43% of new HIV diagnoses. Women diagnosed with HIV in 2003–2004 were predominantly from sub-Saharan Africa and were infected through heterosexual intercourse, often tested during pregnancy. The low proportion of drug users among those discovering their HIV-positive status in 2003 and the decline in AIDS cases over the past five years confirm the reduction in HIV transmission within this population. Virological surveillance combined with mandatory reporting of HIV infection shows that "non-B" subtype viruses, which were a minority in France in the 1990s, account for half of the HIV-positive cases identified in 2003–2004. (R.A.)