By 30th September 1985, 21 countries were taking part in a network of AIDS surveillance in Europe. The data collected by each country are centralized in one of the WHO Collaborating Centres on AIDS, located in Paris (France). The cases reported are analysed according to sex, age, disease category, date of diagnosis, geographic origin, and distribution according to risk groups. The results of this surveillance enable the characteristics of this epidemic to be described in Europe and provide a useful tool for adapting public health strategies to the respective conditions in each country.