There is no, so far, a rational method of therapy based upon the etiology of autoimmune Graves' ophthalmopathy. As a malignant Graves' ophthalmopathy we defined the most severe eye changes leading to the sight loss or permanent disability of vision which are classified as exceeded class 3c according to the eye changes classification of the American Thyroid Association [27]. The aim of the study was to develop the most efficacious method of therapy for malignant Graves' ophthalmopathy. The material consisted of 206 patients treated according to the 3-stage method: 1-st--corticotherapy, 2-nd--radiotherapy, including linear accelerator, 3-rd--orbital decompression. Moreover, in four patients plasmapheresis was applied and in additional five cyclosporine was administered. In all 206 patients the estimation of the results of the treatment was based on the Donaldson ophthalmopathy index [4]. It has been proved that corticotherapy combined with linear accelerator radiotherapy has been the most efficacious method of treatment. It has also the least number of side effects. Orbital decompression as the 3-rd stage of treatment was employed in those cases in which the previous two stages of medical therapy were unsuccessful.