Although reproduction and development are major endpoints for environmental and human health assessments in many federal government programs, growing concern about risks posed by endocrine disrupting substances (EDS) has highlighted the need to detect subtle effects mediated through endocrine systems. Internationally, screening and testing programs in the United States, Japan and Europe, and the activities of international agencies such as the OECD, will have a profound influence on how Canada will address this issue in the future. It is critical that Canada be proactive, identify knowledge gaps from a Canadian perspective, and anticipate international developments that may influence Canadian policy. The complexity and urgency of the EDS question spurred the Five Natural Resource Departments Endocrine Disrupting Substances (5-NR EDS) Working Group to hold a multi-departmental, multi-stakeholder, workshop to address key issues in assessing risks of EDS to Canadians and the Canadian environment. The following is a summary of the major conclusions, research priorities and recommendations from the workshop held at the Grandview Inn, in Huntsville, Ontario, February 13–17, 2000.