We applied continuous intraoperative neuromonitoring (CIONM) during video-assisted thoracoscopic surgery (VATS) lobectomy for left lung cancer and evaluated its safety and usefulness. An electrode was attached to a double-lumen tube, and placed at vocal cord level to detect the EMG signal evoked by vocal cord movement. Before 4 L lymph node dissection, an automatic periodic stimulation device was applied to the vagus nerve to stimulate vagus nerve continuously. Surgery was suspended if the amplitude decreased lower than the threshold and was resumed when the amplitude recovered. Ten patients (6 male, 4 female) were enrolled. CIONM was successfully performed in all patients without technical failure, and there was no hemodynamic instability. Amplitude decreased below the threshold in four patients. One patient did not recover amplitude and experienced transient vocal cord palsy. In the three other patients, the amplitude recovered above the threshold and no vocal cord palsy occurred. The six patients who did not exhibit amplitude decrease experienced no vocal cord palsy. Our results suggest that CIONM may be applied safely for VATS left lobectomy and may be used to predict postoperative vocal cord function. This approach may be helpful to prevent RLN injury during VATS left lobectomy.