Background: Hypoxia is not uncommon in elderly patients during painless gastrointestinal endoscopy. This study aimed to determine the effectiveness of transcutaneous electrical acupoint stimulation (TEAS) in reducing the occurrence of hypoxia symptoms in elderly patients. Methods: Patients were randomly and equally grouped into sham control (n = 109) or TEAS group (n = 109) by using the random number table method. Patients in the TEAS group received electrical stimulation at the bilateral ST36 points 30 min before the examination until the end of the painless gastrointestinal endoscopy. Patients in the control group only had electrodes attached to bilateral nonacupoints in a similar pattern as the TEAS group without electrical stimulation. The primary endpoints measured were the incidence of hypoxia and severe hypoxia. The secondary endpoints included propofol dosage, sedation-related adverse events, hemodynamic parameters, surgical duration, patient recovery time, pain score, patient satisfaction, anesthesiologist satisfaction, and endoscopist satisfaction. Results: Of the 251 patients who participated in this study, 218 patients ended up completing the final study. The primary outcome was that, compared with group control, the incidence of hypoxia in group TEAS was reduced by 11% (19.3% vs. 8.3%, p=0.018) and the incidence of severe hypoxia did not show a significant change (7.3% vs. 2.8%, p=0.122). And there was a significant decrease in the occurrence of patients requiring emergency airway assistance (increased oxygen flow: 16.5% vs. 6.4%, p=0.019, jaw thrust: 11.0% vs. 3.7%, p=0.038, mask-assisted ventilation: 5.5% vs. 1.8%, p=0.015). Conclusion: TEAS can reduce the incidence of hypoxia in elderly patients undergoing painless gastrointestinal endoscopy. Trial Registration: ClinicalTrials.gov identifier: ChiCTR2200059465.Copyright © 2024 Wenyu Zhou et al.