During preoperative examination of 194 patients scheduled for orbital decompression for Graves' ophthalmopathy, it was noted that 29 had never been clinically hyperthyroid. These patients did not differ appreciably from those who had had hyperthyroidism, in terms of age distribution, sex ratio, presenting eye manifestations, or rate of progression of ophthalmopathy. In 81% of the patients with hyperthyroidism, the date of the first eye manifestations was symmetrically distributed within 18 months before or after the time when hyperthyroidism was diagnosed. These observations do not support the viewpoint that radioiodine therapy or surgical intervention initiates the ophthalmic process. The observations focus attention on the need for etiologic theories to address the usually close linkage between thyrotoxic and ophthalmic expressions of Graves' disease rather than on the exceptions to a general rule.