Background: Gallbladder (GB) cancer shows high prevalence in South Korea, and tends to be fatal. In surgically fit patients, radical resection aiming R0 margin combined with lymphadenectomy is the mainstay of curative-intent therapy. In spite of R0 resection, however, high recurrence rate is observed in GB cancer, demanding a need to find out risk factors related to recurrence after surgery. Methods: This is a single center, retrospective cohort study conducted on 148 patients with GB cancer who underwent R0 resection between January 1st, 2014 and December 31st, 2019. Several variables were analyzed with statistical tools to identify risk factors related to prognosis. Relapse free survival (RFS), defined as time from treatment of disease to any event, was analyzed with Cox regression analysis. Results: Based on statistical analysis, risk factors related to RFS were age over 65 (hazard ratio [HR] 3.82, 95% confidence interval [CI] 1.71 – 8.56, p= .001), glycated hemoglobin (HbA1c) level more than 6.5% (HR 2.72, 95% CI 1.31 – 5.66, p=0.007), surgical T stage more than T3 (HR 5.60, 95% CI 3.05 – 10.25, p<0.001), surgical N stage more than N1 (HR 4.07, 95% CI 2.25 – 7.36, p<0.001), pathologic differentiation of moderate or poor differentiation (HR 2.80, 95% CI 1.46 – 5.37, p=0.002), reversed albumin-globulin ratio (HR 0.16, 95% CI 0.06 – 0.40, p<0.001), and high gamma glutamyl peptidase (GGT) level (HR 1.00, 95% CI 1.00 – 1.00, p<0.001). Conclusions: Advanced pathologic stage and high inflammatory marker levels, reflecting high tumor burden, were related with poor surgical outcome. Interestingly, high HbA1c level was related to reduced RFS as well. In conclusion, active screening for early detection, reducing inflammatory conditions, and managing diabetes might enhance RFS after R0 resection of GB cancer.