Introduction: Feeding constitutes one of the ancestral knowledge perpetuated in indigenous communities, with peculiar beliefs and customs for the puerperium, about what to eat and what not to eat. Objective: To describe the beliefs and customs of Nahua women during the immediate postpartum period and their implications for Nursing. Methods: Qualitative ethnographic study, carried out in the native communities of Axtla de Terrazas in San Luis de Potosí, Mexico, between March and July 2019. The population consisted of 50 postpartum mothers from that community. The sample, composed of 14 mothers, was non-probabilistic by convenience and achieved by the criteria of saturation and redundancy of the data. The data were collected by participant observation and ethnographic interview, with prior informed consent, and then processed in an artisanal manner according to the thematic analysis. Results: Three categories emerged: a) Adequate foods that contribute to the recovery of the postpartum women. b) Inadequate foods that affect the postpartum women´s health. c) Foods that increase or decrease the production of breast milk and generate discomfort to the neonate. Conclusions: Nahua women follow the indications of grandmothers and midwives regarding the foods whose consumption is allowed or not during the mediate puerperium, since it is important for their recovery and milk production. Further studies are needed to identify whether mothers receive adequate nutritional requirements, as they avoid nutritious foods such as eggs, milk, red meat, some fruits and vegetables. © 2022, Editorial Ciencias Medicas. All rights reserved.