Background Although proximal gastrectomy (PG) is widely accepted as a function-preserving operation for early upper-third gastric cancer, postoperative disorders, such as reflux or gastric stasis, have often been pointed out. From the perspective of postoperative disorder, the choice of total gastrectomy (TG) or PG for such cancers is still controversial. By using the newly developed Postgastrectomy Syndrome Assessment Scale (PGSAS)-45, the quality of life after TG and PG was compared. Methods The PGSAS-45 consists of 45 items composed of the SF-8 and GSRS scales and 22 new items. The main outcomes are measured by seven subscales (SS) covering symptoms, physical and mental component summary (SF-8), meals (amount and quality), ability to work, dissatisfaction for daily life, and change in body weight. A total of 2,368 eligible questionnaires were acquired from 52 institutions. From these, 393 patients with TG and 193 patients with PG were selected and compared. Results The PG was better than TG in terms of body weight loss (TG 13.8 % vs. PG 10.9 %; p = 0.003), necessity for additional meals (2.4 vs. 2.0; p \ 0.001), diarrhea SS (2.3 vs. 2.0; p = 0.048), and dumping SS (2.3 vs. 2.0; p = 0.043). There were no differences in the other main outcome measures.Conclusions Proximal gastrectomy appears to be valuable as a function-preserving procedure for early upperthird gastric cancer.