The incidence of polyneuropathy in patients with hypothyroidism is not precisely known, but some studies report that about 25% to 42% of patients may show neuropathic clinical signs. We report a case of autoimmune poliglandular syndrome type 2 (APS-2), whose initial presentation was hypothyroid polyneuropathy. A 41-year-old man complained of slowly progressive paresthesias and weakness affecting all four limbs, and associated with frequent drowsiness, weakness, cold intolerance, dizziness, nausea, and craving for salt. General physical examination showed hyperpigmentation of skin and mucous membranes, and hypotension. Neurological examination showed global, deep, and symmetrical hyporeflexia with slight signs of superficial hypoesthesia in the limbs. Electrodiagnostic studies (ENMG) together with laboratory tests, confirmed the suspicion of Hashimoto’s thyroiditis associated with Addison’s disease featuring the picture of APS-2. The patient was treated with fludrocortisone 0.05 mg/day and levothyroxine 100 mcg/day, and showed gradual and complete resolution of complaints. Changes were found in general physical and neurological examinations. ENMG repeated six months later showed complete resolution of neuropathy. This report shows a rare case of APS-2 presented as polyneuropathy hypothyroidism, and reinforces the importance of dosing thyroid hormone in polyneuropathy syndromes. Levothyroxine replacement was shown to be effective in reversing clinical and electrophysiologic neuropathy.