Introduction Remimazolam is a novel short-acting benzodiazepine that exhibits sedative and hypnotic properties without compromising respiratory function and while maintaining haemodynamic stability. Its safety and efficacy have been demonstrated to be non-inferior to those of propofol in the context of general anaesthesia. Nevertheless, the non-inferiority in terms of postoperative recovery quality in obese patients has not been established. Thus, we conducted a prospective, randomised, parallel-group, non-inferiority study to compare remimazolam-based general anaesthesia with propofol-based general anaesthesia on the postoperative quality of recovery (QoR) in patients undergoing laparoscopic sleeve gastrectomy. Methods and analysis All participants meeting the included criteria will be enrolled after signing an informed consent form. Patients will be randomly allocated to either the propofol group (n=63; induction and maintenance with propofol) or the remimazolam group (n=63; induction and maintenance with remimazolam). The primary endpoint of the study is the 15-item QoR Scale assessed at 24 hours postoperatively. Secondary endpoints include the doses of anaesthetic required for loss of consciousness (LOC), the time to LOC, the time to recovery of consciousness, the total amount of anaesthetic administered during the surgery and the incidence of hypotension and bradycardia. Additionally, postoperative profiles of pain, nausea and vomiting, delirium, intraoperative awareness, adverse events and patient satisfaction will be collected. Statistical analyses will be performed using IBM SPSS Statistics V.26.0 and GraphPad Prism V.5.01. Statistical significance is set at two-sided p values<0.05. Ethics and dissemination Ethical approval was obtained from the ethics committees of Beijing Chaoyang Hospital, Capital Medical University (No. 2023ke715-1). The findings will be disseminated in peer-reviewed publications.