Background. Weekly multimicronutrient supplementation was initiated as an appropriate intervention to protect poor urban populations from anemia. Objective. To identify the lessons learned from the Integrated Food Security Program (Programa Integrado de Seguridad Alimentaria [PISA]) weekly multimicronutrient supplementation program implemented in poor urban populations of Chiclayo, Peru. Methods. Data were collected from a 12-week program in which multimicronutrient supplements were provided weekly to women and adolescent girls 12 through 44 years of age and children under 5 years of age. A baseline survey was first conducted. Within the weekly multimicronutrient supplementation program, information was collected on supplement distribution, compliance, biological effectiveness, and cost. Results. Supplementation, fortification, and dietary strategies can be integrated synergistically within a micronutrient intervention program. Conclusions. To ensure high cost-effectiveness of a weekly multimicronutrient supplementation program, the following conditions need to be met: the program should be implemented twice a year for 4 months; the program should be simultaneously implemented at the household (micro), community (meso), and national (macro) levels; there should be governmental participation from health and other sectors; and there should be community and private sector participation. Weekly multimicronutrient supplementation programs are cost effective options in urban areas with populations at low risk of energy deficiency and high risk of micronutrient deficiencies. © 2006, The United Nations University.