Thyrotoxic periodic paralysis (TPP) is a rare disease of muscle paralysis associated with hypokalemia and thyrotoxicosis. Hypokalemic periodic paralysis can be caused by potassium channelopathy or thyroid dysfunction. Thyrotoxic hypokalemic periodic paralysis is far more common in Asian males aged between 20 to 40 years and rare in children and adolescents. Clinical symptoms with motor paralysis were recovered just after treatment of potassium, propranolol, and methimazole. However, thyroid function tests were not normalized until 3 month treatment of methimazole and propranolol. We report a 17-year-old patient diagnosed with Graves' disease with TPP. Thyroid function test should including in periodic paralysis patient's evaluation.