Grave's ophthalmpathy occurs usually in association with hyperthyroidism. However, when exposure keratopathy or pressure optic neuropathy threatens vision, more vigorous treatment is indicated. Unfortunatelly, systemic steroid therapy tends to provide only a temporary remission, and it may cause serious side effects. Irradiation of the orbit is unpredictable and side effect including carcinogenesis. Recently the authors experienced two cases with exophthalmos which were treated by transantral ethmoidal orbital decompression through a Caldwell-Luc approach. Both of then improved visual acuity and cosmetic appearance without postoperative complication. Postoperative result was good.