Aim of the study: Hepatic changes have been described during the refeeding syndrome due to increase in enzymes and hepatomegaly; however, they have not been properly described. Thus, the objective of this study was to investigate the hepatic histological characteristics and biochemical markers of hepatic steatosis in Wistar rats with refeeding syndrome. Material and methods: Thirty male Wistar rats were allocated to one of three groups: C, F or R. The animals from group C received an AIN-93 diet for 96 hours, and were then sacrificed. Animals allocated to group F were fasted for 48 hours and sacrificed. Animals from group R were also fasted for 48 hours, but were refed for another 48 hours, with AIN-93. The liver, blood and epididymal and retroperitoneal fats were collected. Results: Data obtained in groups F and R show the changes observed in refeeding syndrome, during starvation and refeeding. The serum glucose, magnesium, potassium and phosphorus, in group F, decreased. There was no evidence of hepatic steatosis. Hypophosphatemia, hypomagnesemia and hypokalemia were also observed in group R, confirming refeeding syndrome. The main histological characteristic, in this group, was the extensive presence of ballooning degeneration. This is the first article that has detected such change in liver structure, due to refeeding syndrome. The possible causes are: retention of sodium, causing whole body edema; and/or dysfunction of the sodium/potassium pump of the hepatocytes, as a result of hypophosphatemia. Conclusions: This is the first description of an animal model of hepatic severe ballooning degeneration induced due to refeeding syndrome.