A 31-year-old male patient with type Ia glycogen storage disease was admitted to our department complaining of general fatigue and right hypochondriac pain. He exhibited massive hepatomegaly with systemic hypoglycemia, lactic acidosis, hyperuricemia, hyperpyruvatemia and hyperlipemia. The failure of blood glucose levels to increase after a glucagon loading test, and a reduced lactate level on glucose tolerance test were also observed. Various imaging techniques suggested hepatic adenoma with hemorrhage in the tumor, which was confirmed histologically. There was a complete absence of glucose 6-phosphatase activity, as determined by an enzyme assay on resected liver specimens, which proved the case to be type Ia glycogen storage disease. We also reviewed all previously reported cases of hepatic tumor and glycogen storage diseases. We conclude that, since hepatic adenoma is not rare in this disease, and is complicated by hemorrhage, rupture and malignancy, careful follow-ups are necessary.