Hepatic glycogenosis (HG) is a rare complication of long-standing poorly controlled type 1 diabetes mellitus (T1DM), which is often misdiagnosed as non-alcoholic fatty liver disease (NAFLD). Despite the existence of several reports in the literature, it still is underrecognized, even among gastroenterologists. Differential diagnosis between these entities is essential since they have different prognoses.We report a case of an 18-year-old female, with a medical history of poorly controlled T1DM, admitted to an intensive care unit with severe diabetic ketoacidosis (DKA). Upon admission, aminotransferases were significantly elevated; bilirubin and coagulation tests were normal. Despite adequate DKA treatment, she had persistently elevated aminotransferases and hyperlactacidemia. Imaging studies showed hepatomegaly and bright liver parenchyma. Extensive laboratory workup was negative for other causes of liver disease. So, a liver biopsy was performed, which was consistent with the diagnosis of HG. Under strict metabolic control, she had progressive improvement, achieving biochemical normalization within 6 months. This case highlights the need for clinicians to be aware of this condition due to non-negligible differences between HG and NAFLD, with the latter progressing to fibrosis, and ultimately cirrhosis and hepatocarcinoma. On the opposite, HG is considered a benign condition, associated with an excellent prognosis that can be reversible after adequate metabolic control. Liver biopsy remains the gold standard method for HG diagnosis since it can distinguish it from NAFLD.