Most pancreatic cancers are pancreatic ductal adenocarcinomas. This is an extremely lethal disease with poor prognosis and almost no treatment choices. Considering the profound role of the pancreas in the human body, malfunction of this organ can significantly affect quality of life. Although multiple metabolic pathways are altered in cancer cells, certain metabolic gene signatures may be critical for immunotherapy. The reprogrammed metabolism of glucose, amino acids, and lipids can nourish the tumor microenvironment (TME). Previous studies have also shown that reprogrammed metabolism influences immune responses. Tumor-infiltrating immune cells in the TME can adapt their metabolism to blunt the immune system, leading to immunosuppression and tumor progression. The identification of metabolism-related genes (MRGs) associated with immune reactions in pancreatic cancer may lead to improved treatments. This review highlights the characteristics of MRGs in pancreatic cancer and suggests that enhanced anti-cancer therapies could be used to overcome resistance to immunotherapy.