Background There is a paucity of confirmatory randomized controlled trials (RCTs) comparing the effectiveness of totally laparoscopic distal gastrectomy (TLDG) vs laparoscopy-assisted distal gastrectomy (LADG) for early gastric cancer (EGC). Methods A phase III, prospective, multi-center RCT was conducted, wherein patients (n = 442) with clinical stage I gastric cancer eligible for laparoscopic distal gastrectomy were randomized 1:1 to the TLDG or the LADG group. Postoperative morbidity and quality of life (QoL) were compared. Results In total, 422 patients were assessed (TLDG, 216; LADG, 206) in the modified intention-to-treat (mITT) analysis. The morbidity rate did not differ significantly between the two groups (TLDG, 6.0%; LADG, 5.8%; P = 0.93). The 90-day mortality rate was comparable between the groups (TLDG, 0.5%; LADG, 0.0%; P > 0.99). TLDG was significantly associated with a lower pain score compared with LADG in patients with a BMI of >= 25 kg/m(2) (P = 0.002) at 24 h postoperatively. Moreover, TLDG significantly improved QoL in terms of C30 social functioning at 3 and 6 months (P = 0.03 and P = 0.04), C30 global health status at 3 months (P = 0.02), and STO22 body image at 3 months (P = 0.01), with differences dissipating at 12 months. Conclusions TLDG is not superior to LADG in terms of postoperative morbidity and mortality, but it provides better C30 social functioning at 3 and 6 months, C30 global health status and STO22 body image at 3 months, and reduces early postoperative pain for patients with a BMI of >= 25 kg/m(2).