Background and Aims In radical gastrectomy for proximal gastric cancer, bleeding and spleen damage are likely to occur when dealing with short gastric vessels, especially in some obese patients with short spleen-gastric ligaments at the upper pole of the spleen. The author's team has previously used a surgical method of pre-expanding the posterior gastric space, which effectively solves this problem. This study was performed to compare the clinical efficacy of laparoscopic proximal gastrectomy with pre-expansion of the retrogastric space versus conventional laparoscopic proximal gastrectomy, and explore the value of the pre-expansion method in laparoscopic proximal gastrectomy for gastric cancer.Methods The clinical data of 196 patients who underwent laparoscopic proximal radical gastrectomy in the Department of Oncology of the First Affiliated Hospital of Bengbu Medical College from January 2019 to December 2021 were retrospectively analyzed. Of the patients, 99 cases underwent radical proximal gastrectomy with pre-expansion of the retrogastric space (study group), 97 cases received conventional proximal gastrectomy (control group). The clinical variables were compared between the two groups of patients.Results There were no significant differences in general information such as age, sex, BMI, tumor location, tumor stage, surgical method, and esophagojejunostomy method between the two groups (all P>0.05). All patients in both groups completed the laparoscopic surgery uneventfully, with the same range of lymph node dissection and without conversion to open surgery. Compared with the control group, the study group had a significantly shorter average operative time [(100.3±25.8) min vs. (130.7±43.2) min, P=0.000] and significantly less average intraoperative blood loss [(35.0±5.7) mL vs. (44.9±4.7) mL, P=0.000]. Splenic injury occurred in 5 cases (5.2%) in the control group during the surgery, while no intraoperative spleen injury occurred in the study group, but the difference was not statistically significant (P>0.05). There were no statistically significant differences between the two groups in terms of the number of lymph node dissection, postoperative drainage volume, drainage time, postoperative hospital stay, hospital costs, and incidence of surgical complications (all P>0.05). No serious postoperative complications occurred in both groups of patients.Conclusion The surgical method of pre-expanding the posterior gastric space in laparoscopic proximal gastrectomy has the advantages of less intraoperative bleeding, shorter operation time, and reduced iatrogenic splenic injury. So, it is recommended for clinical use.