Ophthalmopathic Graves' disease (endocrine ophthalmopathy) is difficult to diagnose with certainty in the absence of confirmatory laboratory studies. In 11 of 15 patients with proven Graves' ophthalmopathy who were studied with contact B-scan ultrasonography, distinct evidence of orbital edema was demonstrated. Since these abnormalities were not encountered in any of eight patients with tumorous invasion of the orbit causing proptosis, or in any of 50 patients studied for intraocular pathology, it is concluded that contact B-can echography is a valuable diagnostic tool and should be utilized early in the study of all patients with orbital disease.