An analysis is presented of the treatment of 103 patients with thymoma, 56 with myasthenia gravis and 47 without. In a 1966 report on the first 63 patients, it was stated that the presence of myasthenia and the finding of local tumor invasion at operation were ominous prognostic indicators. The augmented series suggests that myasthenia no longer carries this stigma, possibly because of improved methods in its management in patients who have undergone operation.