A massive incorporation of ultra-processed products into young children’s diets worldwide and in Mexico has been documented. The aim of this study is to understand the role of sociocultural factors in principal caregivers’ decisions to give a type of ultra-processed food to children under age five, called ‘comida chatarra’ (‘junk food’ in English), usually includes sugar-sweetened beverages, sweet and salty snacks, and sweet breakfast cereals. We conducted a descriptive, observational qualitative study. The research was conducted in urban and rural communities in two Mexican states. Twenty-four principal caregivers were equally distributed between the two states and types of communities. They were interviewed in person. Phenomenology underpinned this study. Results highlight the preponderant role of culture in food choices and feeding practices with junk food. Local culture influences child-feeding with ultra-processed products through social norms, knowledge, or socially constructed attitudes. These social norms, built in the context of abundant ultra-processed products and omnipresent marketing, ‘justify’ children’s consumption of junk food. They acquire these products from the principal caregivers, family members, and neighbors, among others, who reward and pamper them. These actors also define what amount (small amounts) and when (after meals as snacks) children are given these products. Cultural factors must be considered in the development of effective public policies and programs that aim to change the culture around ultra-processed products among children and avoid their consumption.