In what ways can the process for developing Dietary Reference Intakes (DRIs) be enhanced? The workshop entitled "The Development of DRIs 1994-2004: Lessons Learned and New Challenges" offered a valuable window into the issues and challenges inherent in the development of nutrient reference values. The dialogue-carried out under the auspices of the Institute of Medicine (IOM), Food and Nutrition Board (hereafter referred to jointly as the IOM)-was enriched by the 10 years of experience in deriving the expanded set of values known as the DRIs, plus the decades of experience that grounded the earlier Recommended Dietary Allowances for the United States and the Recommended Nutrient Intakes for Canada. The lessons learned and the knowledge gained will guide decisions about the next phase of the DRIs. To paraphrase one participant, we are now asking better questions. In 2006, the IOM, with support from the United States and Canadian governments, undertook an effort to synthesize the research needs identified during the 10 years of DRI development. While the workshop summarized here was predicated on the fact that the development of DRIs is improved by better data, its focus was different. Its goals were to examine the framework and conceptual underpinnings for developing DRIs and to identify issues important for enhancing the process of DRI development. The workshop was designed to use the existing framework for DRI development as a basis for the discussions and to consider the components of the framework in sequence. Consideration of the pros and cons of the current conceptual underpinnings of the framework opened the workshop, followed by the general "road map" for decision making and the needed scientific criteria. Next, the challenges associated with providing guidance for users were explored. The Development of DRIs 1994-2004: Lessons Learned and New Challenges: Workshop Summary explains an array of issues germane to the future process for developing DRIs, including strategies for updating and revising existing DRIs and opportunities for stakeholder input.