In 2001, students and professionals from 13 nations were hosted by UNICEF for the International Workshop on Multi-Micronutrient Deficiency Control in the Life Cycle in Lima, Peru, May 30-June 1, 2001. Workshop participants engaged in both narrow and broad discussions of ways to combat multiple micronutrient deficiencies in developing countries. Preliminary data from four common-protocol studies conducted in Peru, South Africa, Indonesia, and Vietnam were presented. Participants also discussed the immediate, preliminary, and interim issues that could guide both policy and planning of future studies of multiple micronutrient deficiency. Among the studies highlighted was the International Research on Infant Supplementation (IRIS) I trial.A review of IRIS I yielded some confirmation of the efficacy using a crushable "foodlet" (i.e., cross between food and tablet) as a supplementation vehicle, as well as concerns about potential adverse consequences of nutrient-nutrient and nutrient-nutriture interactions. Other plenary topics illustrated the practical matters of how the IRIS I logistics and operations were built, and several focused on how to best design follow-up research on infant supplementation. Finally, a series of working groups allowed for in-depth discussions on the topics of community and policy, monitoring and implementation, and research. Researchers continue to try to identify efficient and effective programs suited to the low-income settings in which infant multimicronutrient malnutrition occurs. The papers in these proceedings elaborate on several aspects of the IRIS study, and they are published in the hope that their analysis by readers will produce wider dissemination of the details of this devastating problem.