Aims: To compare the long-term outcomes of non-thymomatous myasthenia gravis (MG) patients receiving pre-thymectomy (Pre-CS) or post-thymectomy corticosteroid (Post-CS) therapy. Methods: In a retrospective cohort study, 41 patients with MG were treated with Pre-CS therapy, and 110 were treated with Post-CS therapy. Results: In the MG cohorts, 9 of 40 patients (22.5%) in the Pre-CS group vs. 28 of 105 patients (26.7%) in the Post-CS group achieved a complete remission (CR) at 1 year, 29.7% (11/37) vs. 38.6% (32/83) at 2 years and 36.4% (8/22) in the Pre-CS group vs. 50.0% (28/56) in the Post-CS group achieved a CR at 5 years. For the entire population, Post-CS therapy (hazard rate [HR] 3.042, p = 0.020) was a positive predictor for remission, and a long preoperative interval (HR 0.936, p = 0.030) was a negative predictor. In 98 original ocular MG patients, Post-CS therapy (HR 2.663, p = 0.014) and an age at onset >= 15 years (HR 4.865, p = 0.001) were positive predictors for remission. Discussion: Post-CS therapy with a shorter preoperative interval increases the likelihood of CR in postpubertal and adult patients. (C) 2017 S. Karger AG, Basel