Thyroid eye disease (TED) is the most common extrathyroidal manifestation of Graves' disease. Incomplete understanding of its pathogenesis has hindered development of targeted therapies that might alter the natural course of disease. Smoking cessation and maintenance of euthyroidism appear to reduce the rate of onset and severity of TED. Recent evidence suggests that selenium may lessen the inflammatory symptoms in mild disease. Corticosteroids remain the primary treatment for patients with moderate to severe active TED. Surgical decompression is commonly undertaken in the chronic stable phase, and only rarely in the active phase when vision is threatened by compressive optic neuropathy. Orbital radiotherapy remains an adjunctive strategy during active disease. Targeted immunotherapies have the potential to alter disease progression, but further evidence is needed to establish safety and efficacy. In this article, we review evidence from prospective therapeutic trials of several treatment modalities. We focus on moderate to severe active TED.