BACKGROUND: Converse Ω anastomosis is a recently developed technique of delta-shaped anastomosis for intracorporeal gastroduodenostomy to simplify the anastomotic procedures and reduce their potential risks. This study aimed to evaluate the safety and effectiveness of converse Ω anastomosis, comparing it with conventional extracorporeal Billroth-I anastomosis after laparoscopic distal gastrectomy (LDG) for gastric cancer. PATIENTS AND METHODS: Among 169 gastric cancer patients who underwent LDG with Billroth-I anastomosis anastomosis between April 2013 and March 2018, we selected 100 patients by propensity score matching (50 in the converse Ω anastomosis group and 50 in the extracorporeal anastomosis group). Patients' characteristics, intraoperative outcomes, postoperative complications, and survival time were compared between the 2 groups. RESULTS: Median anastomosis time was significantly longer in the converse Ω group than in the extracorporeal group (40.0 vs. 30.5 min, P=0.005). However, the total procedure time did not differ significantly between the groups. Intraoperative blood loss volume was significantly lower in the converse Ω group than in the extracorporeal anastomosis group (40 vs. 120 mL, P<0.001). There were no significant differences in the number of dissected lymph nodes, postoperative morbidity, mortality, or length of hospital stay. The postoperative body mass index and the prognostic nutritional index did not differ between the groups 1 year after surgery. There were no significant differences in overall survival and relapse-free survival between the 2 groups. CONCLUSIONS: Converse Ω anastomosis is feasible and safe. This novel technique can be adopted as a treatment option for reconstruction after LDG in patients with early-stage gastric cancer. Therefore, the risks and benefits of converse Ω anastomosis after LDG should be confirmed in larger cohorts.