The coincidence of thyroid ophthalmopathy and ocular myasthenia gravis is a defined but rather rare condition. A 30-year-old female patient was admitted with complaints of weight loss, sweating, palpitation and tremor of both hands for about 4 months. She was diagnosed as having Graves' disease with elevated thyroid hormone levels, diffuse hyperplastic thyroid gland with increased iodine, 131 uptake and positive antithyroid antibodies. Two months after the diagnosis of thyroid disease, she developed diplopia and in the foilowjng days, bilateral ptosis. Orbital magnetic resonance imaging shovved that the lateral and inferior rectus muscles were thickened indicating the infiltration of those muscles. She had positive response to the prostigmine test and elevated acetylcholine receptor antibody levels supporting the diagnosis of myasthenia gravis. She had undergone tymectomy and the pathology specimen revealed thymic hyperplasia. This case demonstrates the comorbidity of thyroid ophthalmoplegia and ocular myasthenia gravis. Ocular involvement by this two different pathologies is a rare condition but should be taken into consideration.