Objectives: to define the concept of Health Education of Hospitalized Patient. Methods: the study used the conceptual analysis based on Walker and Avant strategies: Derivation, Synthesis, and Analysis of the concept. Researchers conducted 35 interviews with nurses who worked in direct care to patients admitted to a Hospital-School, and a bibliographic search on the CINAHL, Medline/PubMed®, Scopus, Web of Science, LILACS, and BDENF databases. Results: the study identified the antecedents, attributes, and consequences of the concept and defined the concept of Health Education of Hospitalized Patient as “the action of sharing knowledge about the promotion, prevention, recovery and rehabilitation concerning to health based on reciprocity between nurses and patients, family members and companions, in a systematized or unsystematic way”. Final Considerations: the identification of antecedents, attributes, consequences, and empirical references enabled the theoretical definition unprecedented of this concept and its applicability in practice, contributing to science and hospital nursing care.