We report the case of a 67-year-old man, with a past medical history of radiotherapy for nasopharyngeal carcinoma, who presented with the classical features of a hyperthyroidism (H), due to Graves' disease, with a high TSH receptor antibodies (TRAb) titre. Thyrostatic therapy was started, with gradual improvement of the symptoms and of the thyroid function tests. Two years later, TRAb became negative and the therapy was stopped. In the following months a previously unknown anterior pituitary insufficiency became evident. Therapy with cortisone acetate, L-thyroxine and testosterone was started, resulting in prolonged normalization of the clinical picture. Six years later a short relapse of H was observed, simultaneously to a new increase of TRAb titre, requiring the transitory interruption of the L-thyroxine therapy. In a few months span H disappeared and central hypothyroidism manifested again, so that the patient is still taking replacement therapy. This case illustrates how H and hypopituitarism are not mutually exclusive diagnoses and how, even if rarely, central hypothyroidism and H could alternate in the clinical history of the same patient.