Malnutrition in all its forms (undernutrition, micronutrient deficiency, overweight and obesity) is a major global challenge, and improving nutrition is a key priority for global development, as recognized in the UN Decade of Action on Nutrition (2016–2025) and the 2030 Agenda for Sustainable Development. In this context, ensuring availability, physical accessibility and affordability of healthy and nutritious food at territorial level is crucial to ensure the achievement of the Sustainable Development Goals (SDGs). In many developing countries, territorial markets are key retail outlets for fruits and vegetables, but also for animal source foods and staple foods. Besides the relevance, data concerning the availability of the different food groups and characteristics of food retailers and consumers in territorial markets are seldom considered in national data collection systems. This publication presents a structured methodology and a series of guidelines for mapping territorial markets, as developed by the Food and Agriculture Organization of the United Nations (FAO), along with representatives of producer organizations and academics.