OBJECTIVE To determine the frequencies of medical and surgical treatments in an incidence cohort of 120 patients with Graves' ophthalmopathy. METHODS We reviewed the community medical records and administered a follow-up questionnaire. RESULTS Of the 120 patients, 89 (74.2%) required either no therapy or only supportive measures. Six patients (5.0%) were treated with systemic corticosteroids. One patient had orbital radiotherapy. Twenty-four patients (20.0%) underwent one or more surgical procedures. The cumulative probabilities of undergoing ophthalmic surgery of any type were 5.0% by one year after the diagnosis of ophthalmopathy, 9.3% after two years, 15.9% after five years, and 21.8% after ten years. The need for surgery was significantly related to age (P < .01; Cox proportional hazards model) but was not significantly dependent on gender (P = .5) or the interaction of age and gender (P = .15). The overall risk of the need for surgery was 2.6 times greater in patients older than 50 years (95% confidence interval, 1.2 to 5.8) than in younger patients. There were no significant differences between tobacco smokers and nonsmokers in the cumulative probabilities of undergoing surgery. CONCLUSIONS In 24 (20%) patients, one or more surgical procedures were used to treat Graves' ophthalmopathy. The probability of surgical intervention was significantly related to patient age (older than 50 years), but it was not related to gender or smoking.