Given the rapid spread of the HIV epidemic and the need to control its transmission among intravenous drug users (IDU), harm reduction strategies have been incorporated in many countries, including Brazil. Considering these aspects and taking into account the emergence of drugs as a core concern on the government's agenda, especially crack cocaine, this article presents some of the contributions acquired from observing and recording the practices of an American model of research and care for IDUs, namely the UFO (You Find Out) Study. Issues such as participants' access and adherence, financing difficulties, sustainability and outcome evaluation were considered. The study involved documental research, systematic observation and interviews with key informants. Some of the UFO features that could contribute to the formulation of harm reduction policies in Brazil are highlighted. The UFO appears to be a successful example of harm reduction initiatives that successfully contact and guarantee the commitment of that risk group, ensuring its access to health services and reducing risks associated with drug use.