The transoral endoscopic thyroidectomy vestibular approach (TOETVA) is the most recently developed minimally invasive technique with no skin incision. For tissue dissection and bleeding control, the use of proper energy devices is very important in endoscopic thyroid surgery. To date, there have been no clinical studies reported regarding which energy device is better in TOETVA, ultrasonic shears or advanced bipolar device. The aim of our study is to determine which energy device is more useful for TOETVA. This study was designed as an open-label, prospective randomized controlled trial in a single university hospital. Patients were randomly assigned to the ultrasonic group or advanced bipolar group before the surgery. From June 2020 to May 2022, 40 patients were enrolled (20 patients were assigned to the ultrasonic group, and 20 patients were assigned to the advanced bipolar group). Primary endpoints were operation time for lobectomy, number of camera cleanings, and blood loss during the lobectomy. Secondary endpoints were pain score, postoperative drainage, and blood chemistry. A single endocrine surgeon had performed all surgeries. There were no significant differences between the two groups in age, sex, body mass index (BMI), tumor location, preoperative cytology, or surgical extent. The time for lobectomy was significantly shorter in the advanced bipolar group (33.8±6.4 vs. 41.9±9.0 minutes, P=0.002). The number of camera cleanings was significantly lower in the advanced bipolar group (2.9±1.6 vs. 5.8±2.5 times, P<0.001). Estimated blood loss was also significantly less in the advanced bipolar group (11.5±17.3 vs. 81.8±99.5 mL, P=0.004). Postoperative hospital stays, drainage, pain score, laboratory findings, and complications were not significantly different between the two groups. According to this study, advanced bipolar device showed better performance, with a shorter operation time, less camera cleaning, and less blood loss. We suggest that advanced bipolar device can be a better choice in TOETVA. ClinicalTrials.gov identifier: NCT04320901.