Simple SummaryThis is a comprehensive analysis of the nutritional status (NS) and immune status of 80 pancreatic cancer (PC) patients undergoing curative pancreatic resection. Higher weight loss (WL) was related to the proximal tumor location. Lower serum total protein, albumin, hemoglobin levels, and PNI were reported in older patients. The higher nutritional risk according to NRS 2002 was associated with higher age, higher WL, lower body mass index (BMI), lower total lymphocyte count, longer duration of hospitalization, neoadjuvant chemotherapy, and preoperative biliary drainage. The lower prognostic nutritional index (PNI) was associated with higher WL, lower serum total protein and albumin concentration, lymphocyte count and higher neutrophil/lymphocyte (NLR), monocyte/lymphocyte (MLR), platelet/lymphocyte (PLR) ratios, and duration of hospitalization. In multiple logistic regression analysis, BMI ≥ 30 kg/m2 and NRS 2002 ≥ 3 predicted postoperative complications. In multiple linear regression analysis, the higher NRS 2002 score was linked with longer duration of hospitalization and longer duration of postoperative hospitalization was associated with a higher complication rate. Nutritional impairment correlated with a systemic inflammatory response in PC patients. Assessment of nutritional and immune status using basic diagnostic tools and PNI and immune ratio calculation should be the standard management of PC patients before surgery to improve the postoperative outcome. The aim of this study was to assess and analyze the nutritional status (NS) and immune status of pancreatic cancer (PC) patients. The retrospective analysis included 80 PC patients undergoing curative pancreatic resection in the Department of Digestive Tract Surgery of the Medical University (Katowice, Poland). Patients were divided by the tumor location (proximal vs. distal), age (≤65 years vs. >65 years), Nutritional Risk Score 2002 (NRS 2002) (<3 vs. ≥3), prognostic nutritional index (PNI) (<45 vs. ≥45), and the presence of postoperative complications (no-complication vs. complication) as well as the use of neoadjuvant chemotherapy (no neoadjuvant chemotherapy vs. neoadjuvant chemotherapy) into two subgroups, which were compared. Significantly higher weight loss was related to the proximal tumor location (p = 0.0104). Significantly lower serum total protein (p = 0.0447), albumin (p = 0.0468), hemoglobin (p = 0.0265) levels, and PNI (p = 0.03) were reported in older patients. The higher nutritional risk according to NRS 2002 was significantly associated with higher age (p = 0.0187), higher weight loss (p < 0.01), lower body mass index (BMI) (p = 0.0293), lower total lymphocyte count (p = 0.0292), longer duration of hospitalization (p = 0.020), neoadjuvant chemotherapy (p < 0.01), and preoperative biliary drainage (p = 0.0492). The lower PNI was significantly associated with higher weight loss (p = 0.0407), lower serum total protein and albumin concentration, lymphocyte count (p < 0.01) and higher neutrophil/lymphocyte (NLR), monocyte/lymphocyte (MLR), platelet/lymphocyte (PLR) ratios, and duration of hospitalization (p < 0.01). In the multiple logistic regression analysis, BMI ≥ 30 kg/m2 (OR: 8.62; 95% CI: 1.24–60.04; p = 0.029521) and NRS 2002 ≥ 3 (OR: 2.87; 95% CI: 0.88–9.33; p = 0.048818) predicted postoperative complications. In the multiple linear regression analysis, the higher NRS 2002 score was linked with the longer duration of hospitalization (b = 7.67948; p = 0.043816), and longer duration of postoperative hospitalization was associated with a higher complication rate (b = 0.273183; p = 0.003100). Nutritional impairment correlates with a systemic inflammatory response in PC patients. Obesity (BMI ≥ 30 kg/m2) and malnutrition (NRS 2002 ≥ 3) predict postoperative complications, which are associate with a longer hospital stay. Assessment of nutritional and immune status using basic diagnostic tools and PNI and immune ratio (NLR, MLR, PLR) calculation should be the standard management of PC patients before surgery to improve the postoperative outcome.