We present the case of a 60-year old woman with painful swelling of the thyroid gland and temporary thyrotoxicosis. 30 years ago she had experienced a period of hyperthyroidism because of Graves' disease. This time thyrotropin-receptor-antibodies were negative, Tc-99 m scan revealed decreased uptake in both lobes (this pattern normalised later on) and fine needle aspiration presented leucocyte infiltration of the thyroid. Three months later hypothyroidism was observed requiring treatment with levothyroxine. The development of subacute thyroiditis and Graves' disease in the same person is rare, autoimmune factors and a possible relationship are discussed.