Background: We investigated the significance of the para-aortic node (PALN) and other regional node metastases (RLN), reflecting malignant histological findings or poor patient prognosis, in patients with biliary duct cancers (BDC) and pancreatic carcinomas (PC) who underwent radical resections at two institutes. Methods: Conventional clinicopathological factors, including metastasis to the PALN and RLN, and surgical outcomes or long-term prognosis in 181 PC and 116 BDC patients between 1994 and 2022 were examined. Results: In patients with PC, cancer metastasis was observed in the RLN and PALN in 54% and 9% of patients, respectively. In patients with BDC, cancer metastasis was observed in the RLN and PALN in 39% and 9% of patients, respectively. Disease-free survival (DFS) and overall survival (OS) in patients with BDC and PALN metastasis were significantly lower than those without PALN metastasis; however, several patients survived over three years. Multivariate analysis revealed that, in patients with BDC, PALN metastasis was an independently related factor of OS, and RLN was an independently related factor for DFS, respectively (p