Industrial fortification of maize flour and corn meal with at least iron has been practiced for many years in several countries in the Americas and Africa, where these ingredients are used in the preparation of many common national dishes. This guideline provides global, evidence-informed recommendations on the fortification of maize flour and corn meal with micronutrients as a strategy to increase the supply of vitamins and minerals that are present in inadequate diets, and therefore contributing to improvement of the health status of populations. The guideline aims to help Member States and their partners in their efforts to make informed decisions on the appropriate nutrition actions to achieve the Sustainable Development Goals (SDGs), in particular, Goal 2: End hunger, achieve food security and improved nutrition and promote sustainable agriculture and Goal 3: Ensure healthy lives and promote well-being for all at all ages. It will also support Member States in their efforts to achieve the global targets of the Comprehensive implementation plan on maternal, infant and young child nutrition and The global strategy for women’s, children’s, and adolescents’ health (2016–2030). The recommendations in this guideline are intended for a wide audience, including policy-makers, their expert advisers, economists, and technical and programme staff in ministries and organizations involved in the design, implementation and scaling-up of nutrition actions for public health, particularly in the design and implementation of appropriate food fortification programmes as part of a comprehensive food-based strategy for combating micronutrient deficiencies. This guideline provides information on the health impact of the fortification of maize flour and corn meal with micronutrients.