The records of 141 patients with myasthenia gravis who had thymomas were reviewed. In this series there were 69 noninvasive tumors and 52 invasive tumors. The five year survival for all patients was 60%, with the invasive group demonstrating a poorer prognosis than the noninvasive. The remission rates for the whole group (both invasive and noninvasive) of myasthenics was quite low (7%). Although the overall survival of this series of patients was relatively high, it is felt that by earlier diagnosis and a more aggressive surgical approach their prognosis will be even better.