AIM:To determine the clinical characteristics of a prospective study of patients with Graves' ophthalmopathy.METHODS:We reviewed clinical manifestations,and medical records of 103 patients in whom Graves' ophthalmopathy WaS diagnosed between 2003 and 2005.RESULTS:Among 103 patients with Graves' ophthalmopathy,48(46.6%)male and 55(53.3%)female(F:M=1.1),with mean age of 45 (range;18-73) years,95 (92.2%)patients had Graves' hyperthyroidism,3(2.9%) had primary hypothyroidism,and 5 (4.8%) were euthyroid.The mean duration of ocular symptoms was 13.2 (range 2-95) months) while the mean duration of dysthyroid symptoms was 39.4(range 6-180) months.Unilaterality was occurred in 12 patients.Eyelid retraction was present in 90 patients (87%),whereas the approximate frequency of exophthalmos was 77.6%(80 patients);restrictive extraocular myopathy.29% (30 patients);evidence of extraocular enlargement on CT-scan in 52 patients of 70 patients (74%) that was evaluated,and optic nerve dysfunction,5.8%(6 patients).22(21%)patients hadglaucoma associated with Graves' ophthalmopathy that 7 (6.7%)of them were normal-tension glaucoma.CONCLUSION:Eyelid retraction Was the most common clinical sign of Graves' ophthalmopathy in our patients.Larger prospective studies are suggested to evaluate both the prevalenoe and possible racial difference in its dinical presentation in Iranian population.