An analysis of activity data from the CDAGs in 1998 and 1999 revealed an increase in the proportion of positive HIV diagnoses in the Île-de-France region. In light of these results, the 2000 and 2001 activity data available for Paris were analyzed without waiting for the full set of national data to be released. Anonymous epidemiological information on HIV-positive individuals was collected from the CDAGs in Paris to aid in the interpretation of this trend. (R.A.).