It is well known that thymoma is often associated with myasthenia gravis. Although ectopic thymoma can be found anywhere from the pharynx to the anterior mediastinum, it is usually benign and has not been reported in association with myasthenic symptoms. Moreover, ectopic thymoma located in the neck region is apt to be misdiagnosed as a thyroid mass or other infiltrative lesion. We report the case of a patient with myasthenia gravis associated with ectopic cervival thymoma, whose myasthenic symptoms were well controlled after removal of the ectopic thymomas.