Antithyroid drugs have mainly been used to obtain euthyroidism in patients with chronic hyperthyroidism, whatever the cause, and for long-term medical treatment of hyperthyroidism due to Graves' disease. Endocrinologists are faced with the problem of potential side effects and a high relapse rate (30-50%) after an apparently successful treatment. Despite the use of antithyroid drugs for more than four decades, controlled prospective studies have only recently been carried out, comparing high- versus low-dose antithyroid drug treatment of Graves' disease. The present review focuses on differences in treatment regimens in various areas of the world, efficiency, side effects, and the possibility of predicting relapse at the end of antithyroid drug treatment. Several surveys have recently been taken concerning treatment strategy in various parts of the world. Despite the obvious limitations of surveys carried out by a questionnaire, these studies represent the first important efforts to analyze and compare medical strategies for the management of Graves' disease in Europe, the USA, and Japan, between 1986 and 1992. There were clear indications that American thyroidologists appear to be giving up on antithyroid drug therapy more readily and opting instead for generalized ablative treatment with radioactive iodine. In Europe, on the contrary, radioiodine remains largely limited to specific conditions, and antithyroid drugs still remain the major first-line therapy for Graves' disease. In the future, immunomodulation--either alone or in combination with antithyroid drugs--might improve the medical treatment of Graves' disease. Despite the well-known limitations of antithyroid drugs, their use is simple, safe, and advantageous; European endocrinologists thus challenge the American tendency to ablate almost all patients with radioiodine.