Background: The frequency of major cancer surgery in the elderly (≥80years) has increased concomitantly with the rise in average age of the population. We assessed early postoperative mortality following hepato-pancreato-biliary (HPB) and gastrointestinal (GI) procedures for common malignancies stratified by age. Methods: The National Cancer Database (2004-2017) was queried for patients who underwent resection for GI (gastroesophageal and colorectal) or HPB (pancreatic adenocarcinoma, biliary tract, and primary liver) cancers. We compared early postoperative mortality (30d and 90d) stratified by age (65-79 vs ≥80years) and procedure, and compared survival outcomes by age and operative vs nonoperative management. Results: A total of 709,358 patients were included. The 30-day mortality ranged from 1.8% to 5.8% among patients 65-79years and from 3.2% to 12.4% among patients ≥80years depending on procedure. The 90-day mortality ranged from 3.6% to 10.6% in patients 65-79years compared to 8.4%-21.0% among patients ≥80years. The overall 90-day mortality was 5.2% for patients 65-79years and 12.0% for patients ≥80years (P < .001). Age ≥80 was associated with worse survival among operatively managed patients with each upper GI, HPB, and lower GI malignancy relative to younger patients on multivariable analysis. However, operative management of patients ≥80years was associated with improved survival relative to nonoperative management. Discussion: Elderly patients suffer higher postoperative mortality after major GI and HPB cancer surgery, but operative management is associated with improved survival among patients ≥80years as compared to nonoperative management. These data are important to contextualize when counseling elderly patients on their treatment options for localized GI and HPB cancers.