The patient was an 11-year-old neutered male Persian cat. He was referred for the chief complaint of dysuria. On presentation, the cat was anorexic for many days and had detectable icterus. Surgical intervention was made to resolve urinary tract obstruction and esophagus tube was placed. Liver biopsy was also performed during surgery and revealed idiopathic hepatic lipidosis. The cat was administrated with intravenous fluid and started multiple and small amount of feedings. Despite aggressive intravenous potassium supplement, the patient still showed severe hypokalemia. The clinical diagnosis of this case was refeeding syndrome.