The rapid spread of HIV infection among intravenous drug abusers plays an increasing role in the AIDS epidemic. In this context the Austrian government changed politics and introduced a methadone maintenance program 1987, to reach more intravenous drug addicts and to stop intravenous drug abuse of this clients. 119 intravenous drug users were anonymously tested for HIV antibodies between April 18 and May 17, 1988 at the out-patient clinic of the Psychiatric University clinic of Vienna and were examined by means of a standardized questionnaire. The data are discussed in respect of the benefits of a methadone maintenance program to decrease HIV-infection among intravenous drug abusers in Vienna.