Objective: Refeeding hypophosphatemia (RH) is common in critically ill patients and is associated with high morbidity andmortality, but the influence on appetite-regulating hormones is unknown. This study aimed to determine the associationbetween serum levels of phosphorus and specific appetite-regulating hormones in critically ill patients. Materials and Methods: This study was performed prospectively in patients admitted to the intensive care unit (ICU). Thestudy included patients aged ≥18 years who were admitted to the ICU and feeding at least 72 hours (h). Serum was obtainedat baseline, 24 h, and 72 h later for concentrations of leptin, adiponectin, ghrelin, resistin, insulin-like growth factor 1 (IGF 1), and glucagon-like peptide 1 (GLP-1). Phosphorus levels were accepted at ≤2.4 mg/dL for RH. Results: Of the 26 cases, 17 (65%) were male. The baseline phosphorus levels at baseline, 24 h, and 72 h were 3.58±0.94mg/dL, 2.61±1.05 mg/dL, and 2.91±0.76 mg/dL, respectively. RH rate was developed 24 h, 72 h, and over time in 38%,15%, and 42% patients, respectively. Adiponectin levels at 24 h were significantly different between patients who developedRH and those who did not develop RH. A positive correlation was observed between 24 h serum adiponectin level and 24 hphosphorus level. A positive correlation was found between baseline serum ghrelin level and baseline phosphorus level. No sig nificant difference was found between RH and insulin, leptin, ghrelin, resistin, IGF-1, and GLP-1 at baseline, 24 h, and 72 h. Conclusion: RH was found to be of high ratio in critically ill patients. Adiponectin level was found to be high at 24 h inpatients with RH.