Objective To assess the feasibility of non-drainage tube after single-port video-assisted thoracoscopic thymectomy in patients with myasthenia gravis (MG). Methods According to whether the thoracic drainage tube was placed after thymectomy, the patients with MG were divided into control group (38 cases) and experimental group (25 cases). The thoracic drainage tube was inserted between the ribs in the control group, and not placed in the experimental group. The clinical data including duration and score of post-operative chest pain and post-operative hospital stay were recorded and analyzed by independent samples t test. Results There was statistically significant difference between the two groups in the duration of post-operative chest pain [(32.7±10.2) h vs. (14.2±2.9) h, P=0.000], the score of post-operative chest pain [(2-6) 3.8 scores vs. (1-5) 2.4 scores, P=0.000], duration of post-operative hospital stay [(5.6±1.0) days vs. (4.9±0.7) days, P=0.016], post-operative chest drainage time [(23.6±8.7) h vs. (0) d, P=0.000] and post-operative thoracic drainage volume [(60.8±9.5) ml vs. (0) ml, P=0.000]. At 3rd day after operation, the results of the chest CT examination showed 38 cases in the control group had a small amount of pleural effusion (<50 ml) and no pneumothorax, and 25 cases in the experimental group had a small amount of pleural effusion (<150 ml) and 2 cases had a small amount of pneumothorax (<10%). At first month after operation, the results of the chest CT examination showed that there were no significant pleural effusion (<30 ml) and no pneumothorax in the two groups. Thoracentesis was not needed in the two groups after operation. Conclusion It is safe and feasible that thoracic drainage tube is not placed after single-port video-assisted thoracoscopic thymectomy in patients with MG. Key words: Myasthenia gravis; Video-assisted thoracoscopic surgery; Thymectomy; Draining tube