OBJECTIVE to describe a theoretical model of nursing care for children with obesity in Primary Health Care. METHODS Grounded Theory and the theoretical/philosophical framework of Virginia Henderson were used. The research was conducted in Family Basic Health Units and in Specialized Services in the city of Campina Grande, Paraíba, Brazil. A total of 24 participants composed four sample groups. Data were collected through semi-structured interviews, between April and October 2015, and analyzed by the constant comparison method. The analysis occurred by initial coding, construction of diagrams and memos, axial coding, selective coding and reflection on the paradigm and on the emerging theory. RESULTS six categories emerged from the data. Nurses worrying about the care of children with obesity as a neglected area in Primary Health Care was the theoretical model. CONCLUSIONS the phenomenon is related to the individuality of nursing care and the need for shared responsibilities.