A surveillance system (LaboVIH) was established in 2001 in medical testing laboratories with two objectives: - first, in 2001 and 2002, a period when mandatory reporting of HIV infection was not yet in effect, to measure HIV testing activity and collect basic information on individuals diagnosed as HIV-positive; - second, to contribute to the interpretation of data from mandatory reporting of HIV infection once it was implemented, by tracking changes in HIV testing activity over time. This article presents the results of this surveillance for the years 2001 and 2002. Data for 2003 are currently being collected from laboratory technicians. (R.A.)