The 34-year old woman, by profession a farmer, presented herself with the symptoms of hypothyroidism, which were confirmed by laboratory investigations. Chronic autoimmune thyroiditis was assumed due to the constellation of primary hypothyroidism in association with elevated thyroid autoantibodies. Substitution with levothyroxine induced a full clinical recovery, but persistent hyperthyroidism occurred even after discontinuation of levothyroxine treatment. Mild ophthalmopathy developed and Graves disease was diagnosed. The primary manifestation of Graves' disease with hypothyroidism was caused by blocking TSH receptor antibodies. Chronic autoimmune thyroiditis, Graves' disease and the importance of thyroid autoantibodies are discussed.