To describe the experience of using the Calgary Family Assessment Model in two family units with child malnutrition, as well as to construct their genogram and ecomap, analyzing the profile of the family structure. This is a case study carried out with two families, with a qualitative approach, developed in a reference unit for early childhood care, located in the city of Fortaleza-CE, from March to May 2023. ethical assessment with CAAE 66662422.8.0000.5049. Family 2 presented a higher risk of food insecurity, since only one of its components (F1) is the breadwinner. In addition, it was found that the therapies used in nutritional monitoring achieved greater adherence in Family 1, correlated with greater access to food, as well as the higher level of education of its members. However, through the application of the Calgary Model of Family Assessment, one can recognize the ability of families to solve problems, as well as inhibitions related to the educational nature that make it difficult to adhere to the interventions offered about child malnutrition.