A CIOMS historical report on the XVIIth Round Table Conference on “Biomedical Research Involving Animals – Proposed International Guiding Principles” organized by CIOMS in December 1983, within the framework of a project for Development of Guiding Principles for the Use of Vertebrate Animals in Biomedical Research, in collaboration with the World Health Organization. The conference brought together scientists from both academia and industry, and representatives of health administrations and of international nongovernmental organizations, including animal welfare organizations. The specific objective of the conference was to discuss and comment on the “Proposed International Guiding Principles for Biomedical Research Involving Animals”.