BACKGROUND: Glycogen storage disease (GSD) is an inherited metabolic disorder affecting glycogen metabolism. The overall incidence of GSD is estimated to be 1 in every 20,000 to 43,000 newborns. GSD is classified into 12 types based on the enzyme deficiency and the tissues affected. Disorders in glycogen degradation may primarily impact the liver, muscles, or both. RESULTS: In this case report, we discuss a patient with end-stage liver disease due to GSD IIIa who was treated with liver transplantation. Following liver transplantation, the patient's cirrhosis was cured. Six years post-surgery, the patient developed elevated creatine kinase levels without any obvious cause, along with occasional lower limb weakness after exertion. Muscle biopsy revealed pathological changes consistent with vacuolar myopathy. CONCLUSIONS: Liver transplantation does not fully cure glycogen storage disease type IIIa myopathy, necessitating ongoing postoperative follow-up with regular creatine kinase monitoring and other laboratory assessments.