ABSTRACT Background: Postoperative complications are a significant concern in patients undergoing gastrointestinal (GI) surgeries, often leading to prolonged hospital stays, increased morbidity, and higher healthcare costs. Malnutrition has been identified as an independent risk factor for adverse postoperative outcomes. This study aimed to evaluate the effect of preoperative nutritional intervention on the incidence of postoperative complications in patients undergoing major GI surgeries. Materials and Methods: A prospective, randomized study was conducted on 120 patients scheduled for elective gastrointestinal surgeries at a tertiary care center. Patients were divided into two groups: Group A (n=60) received standard preoperative care, while Group B (n=60) received individualized nutritional supplementation for 7–10 days prior to surgery, including oral nutritional supplements rich in protein, vitamins, and trace elements. Postoperative complications including infections, anastomotic leaks, wound dehiscence, and prolonged ileus were recorded. Nutritional status was assessed pre- and postoperatively using serum albumin levels and Subjective Global Assessment (SGA) scores. Results: Group B showed a significantly lower incidence of postoperative complications (20%) compared to Group A (38%) (p=0.045). The mean serum albumin level improved in Group B from 2.8±0.4 g/dL to 3.5±0.3 g/dL post-intervention (p<0.01), whereas no significant change was observed in Group A. The rate of surgical site infections was reduced from 15% in Group A to 6.7% in Group B. Mean hospital stay was shorter in Group B (7.2±1.1 days) than in Group A (9.6±1.5 days) (p=0.032). Conclusion: Preoperative nutritional intervention significantly reduces postoperative complications and hospital stay in patients undergoing gastrointestinal surgeries. Optimization of nutritional status before surgery should be considered an integral component of perioperative care.