Purpose: This study systematically evaluated the implications of advanced age on post-surgical outcomes following gastrectomy for gastric cancer using a national database. Materials and Methods: The 2011-2017 National Inpatient Sample was used to isolate patients who underwent gastrectomy for gastric cancer. From this, the population was stratified into those belonging to the younger age cohort (18-59 years), sexagenarians, septuagenarians, and octogenarians. The younger cohort and each advanced age category were compared in terms of the following endpoints: mortality following surgery, length of hospital stay, charges, and surgical complications. Results: This study included a total of 5,213 patients: 1,366 sexagenarians, 1,490 septuagenarians, 743 octogenarians, and 1,614 under 60 years of age. Between the younger cohort and sexagenarians, there was no difference in mortality (2.27 vs. 1.67%; P=0.30; odds ratio [OR], 1.36; 95% confidence interval [CI], 0.81-2.30), length of stay (11.0 vs. 11.1 days; P=0.86), or charges ($123,557 vs. $124,425; P=0.79). Compared to the younger cohort, septuagenarians had higher rates of in-hospital mortality (4.30% vs. 1.67%; P<0.01; OR, 2.64; 95% CI, 1.67-4.16), length of stay (12.1 vs. 11.1 days; P<0.01), and charges ($139,200 vs. $124,425; P<0.01). In the multivariate analysis, septuagenarians had higher mortality (P=0.01; adjusted odds ratio [aOR], 2.01; 95% CI, 1.18-3.43). Similarly, compared to the younger cohort, octogenarians had a higher rate of mortality (7.67% vs. 1.67%; P<0.001; OR, 4.88; 95% CI, 3.06-7.79), length of stay (12.3 vs. 11.1 days; P<0.01), and charges ($131,330 vs. $124,425; P<0.01). In the multivariate analysis, octogenarians had higher mortality (P<0.001; aOR, 4.03; 95% CI, 2.28-7.11). Conclusions: Advanced age (>70 years) is an independent risk factor for postoperative death in patients with gastric cancer undergoing gastrectomy.