National Reference Laboratory on AIDS (NRL AIDS) was established in the National Institute of Public Health by the Ministry of Health in the late 1985. At that time the existence of HIV/AIDS and the potencial spread of this infection/disease even in a socialistic country has been officially recognized. The main tasks of NRL AIDS were and still are the laboratory diagnostic, epidemiology and research of HIV/AIDS. As one of its first steps NRL AIDS introduced HIV antibody testing methods and strongly recommended obligatory screening of all blood donations to assure the safety of blood and blood products. In 1986 NRL AIDS performed the first serological pilot study to gain basic data on HIV infection incidence and prevalence in the Czech population. National HIV/AIDS reporting system has been elaborated at NRL AIDS and connected with the WHO-EC European AIDS Monitoring System. Several national and international collaborative HIV surveillance studies in different population groups are performed and evaluated yearly to monitor the trends in the spread of HIV/AIDS in the Czech Republic. From 1986 through May 1995 a total of 230 cases of HIV infection were reported in the Czech Republic. Of these 62 cases met the criteria for AIDS case definition. Homo/bisexual men are still the most affected population group accounting for 59% of all HIV reported cases. Nevertheless the percentage of heterosexually transmitted infections is constantly increasing, presently accounting for 19% of all infected persons. The activities of NRL AIDS are very broad, including the field of applied research. Several research grants were obtained from the Grant Agency of the Ministry of Health. Results of some of these are included in the National HIV/AIDS Programme of the Czech Republic.