BackgroundSerious consequences leading to the increase of infectious diseases and mortality of children justifies the importance of interventions for eradication of malnutrition. Thus, this study aimed to provide a model for the prevention of malnutrition among children under 5 years old (CU5) in Iran.MethodsThis paper is part of a bigger study, conducted in 2017 using a mixed methods approach. A model for prevention of malnutrition in CU5 was proposed based on the earlier steps, with the cooperation and consultation of experts and specialists. In the final step, a Delphi method was used to determine the validity of the proposed model.ResultsThe main dimensions of the prevention model of malnutrition for CU5 in Iran included four level: basic causes, interventions, outcomes and impact. The proposed interventions are presented based on twelve areas: structural, intersectoral, political, economic, sanitary, health-oriented, research, educational/cultural, evaluation related, production, infrastructures and legal. Based on these areas, 118 solutions were finally selected for the final model. This model is designed based on the current conditions in different regions of Iran, the factors related to child malnutrition, affective context on policy making, the content of previous policies, the process of policy making in Iran, and key stakeholders and actors in policy making.ConclusionIn order to prevent malnutrition, the causing factors should be identified and resolved. The adopted policies should be, more seriously, based on the presence of key stakeholders and actors. Most of the existing nutritional problems among children are because of inappropriate consumerism culture and habits in families and its transfer to children.