Background/Objectives: Nutritional status affects postoperative outcomes, but the effect of standardized preoperative nutritional preparation on morbidity in malnourished patients undergoing pancreatoduodenectomy (PD) remains unclear. This study evaluated preoperative nutritional parameters following the standardization of nutritional screening and intervention in patients undergoing PD. The influence of nutritional parameters on postoperative morbidity was also assessed. Methods: This prospective cohort study was conducted from 2019 to 2021 at the Department of Surgery, University Hospital, Olomouc. A total of 133 patients were categorized nutritionally as "high risk" (weight loss or reduced appetite with restricted intake) or "low risk" (no weight or appetite loss). High-risk patients received enteral supplementation of 600 kcal/day. A multivariate logistic regression model was used to evaluate the association between major postoperative complications and risk factors, including sex, age, ASA score, BMI, weight and appetite loss, malignancy, duct diameter, pancreatic texture, serum albumin, prealbumin, MUST, and NRS2002 scores. Results: Eighty patients (60. 2%) were "high risk," and 53 (39 VSports手机版. 8%) were "low risk. " Major morbidity and 90-day mortality occurred in 24 (18. 0%) and 4 (3. 0%) patients, respectively. No significant differences were observed between high- and low-risk groups in CD morbidity grade, 90-day mortality, POPF, PPH, DGE, or hospital stay. Major morbidity was associated with prealbumin < 0. 2 g/L, duct diameter ≤ 3 mm, soft texture, and male sex, with respective odds ratios of 3. 307, 3. 288, 4. 814, and 2. 374. Conclusions: High-risk patients receiving preoperative nutrition had comparable rates of major complications and POPF as low-risk patients. Low serum prealbumin predicts major postoperative complications after PD. .