This report summarizes the presentations and recommendations from a consultation held in Lausanne, Switzerland (26-28 August 2004) organized by the joint World Health Organization (WHO) - United Nations Programme on HIV/AIDS (UNAIDS) HIV Vaccine Initiative. The consultation discussed issues related to gender, ethnicity, and age in HIV vaccine research and clinical trial recruitment. A special focus of the meeting was the participation of women and adolescents in clinical trials. Also discussed were the experiences and lessons from various research programs, trials, and studies in different countries. Implementing the recommendations from this meeting will require prioritization and active participation from the research community, funders of research, local and national governments, non-governmental organizations, and industry, as well as the individuals and communities participating in clinical trials. This report contains the collective views of an international group of experts, and does not necessarily represent the decisions or the stated policy of the WHO. The contribution of the co-chairs (R. Macklin and F. Mhalu) and the rapporteurs (H. Lasher, M. Klein, M. Ackers, N. Barsdorf, A. Smith Rogers, E. Levendal, T. Villafana and M. Warren) during the consultation and in the preparation of this report is much appreciated. S. Labelle and J. Otani are also acknowledged and thanked for their efficient assistance in the preparation of the consultation and the report.