Objective To investigate the clinical efficacy of esophagogastrostomy using seromuscular double-flap technique following laparoscopy-assisted proximal gastrectomy. Methods The clinical data of one patient with gastrointestinal stromal tumor at the gastric cardia who underwent laparoscopy-assisted proximal gastrectomy in September 2019 was retrospectively analyzed. We reviewed the literature about esophagogastrostomy using seromuscular double-flap technique following proximal gastrectomy and summarized the clinical data. Results This case was a 67-year-old male patient. The patient was diagnosed as gastrointestinal stromal tumor at the gastric cardia by both preoperative imaging and postoperative pathologic examination. Laparoscopy-assisted proximal gastrectomy and esophagogastrostomy using seromuscular double-flap technique was performed. The total operative time and anastomosis time were 280 min and 100 min, respectively. The intraoperative blood loss was 40 mL. The time to the first postoperative flatus was 3 d. The time to the liquid diet was 4 d. The duration of postoperative hospital stay was 8 d. No postoperative short-term complication was found. No reflux esophagitis was shown two months postoperatively with endoscopy. The literature review showed that the occurrence of anastomotic leakage, anastomotic bleeding, anastomotic stenosis, and reflux esophagitis of esophagogastrostomy using seromuscular double-flap technique were 0-4.2%, 0-0.7%, 4.0%-29.1%, and 0-8.3%, respectively. Conclusions Esophagogastrostomy using seromuscular double-flap technique following laparoscopy-assisted proximal gastrectomy was safe and effective in terms of preventing gastroesophageal reflux. It can be applied in highly selected patient with upper-third gastric tumor. High attention is still required to prevent and treat the postoperative anastomotic stenosis.