Background: Refeeding syndrome (RS) can be defined as a set of severe metabolic disorders that may occur in malnourished patients receiving refeeding through enteral or parenteral nutrition. Objectives: A narrative review of scientific literature on RS was primarily focused on its identification of risk factors, diagnostic, and incidence. Methods: A search was carried out for articles through the PubMed database focused on meta-analyses, systematic reviews, case reports, and observational studies on RS. Results: SR is a clinical challenge when initiating nutritional support in malnourished patients, with risks such as electrolyte imbalances, edema and neurological complications. This review presented the wide incidence ranging from 0 to 90%, the heterogeneity of the criteria for the diagnosis of RS, and its risk factors at the hospital setting. Conclusion: RS is complex in hospital settings and is associated with aggressive initiation of feeding, increasing the risk of morbidity and mortality. It is necessary to conduct further research with the strongest methodological bases to validate the usefulness of the diagnostic criteria.