Background: The prevalence of protein-energy malnutrition in surgical patients is seen in 30-50% of surgical patients with gastrointestinal disease. Malnutrition and hypalbuminaemia contribute to increased morbidity and mortality. Serum albumin level is a low-cost key element in nutritional assessment. Clavien-Dindo classification of post-operative complications enables stratification of post-operative complication.Methods: We retrospectively analysed the prospectively maintained data of 136 patients who underwent major gastro intestinal procedures from October 2019 to March 2020. We assessed the pre-operative; intra operative parameters, outcome variables and the postoperative complications were graded according to Clavien-Dindo severity, length of ICU stay, length of hospitalization and mortality.Results: Out of the 136 patients (M: F=3:2), the procedures were hepatopancreaticobiliary (n=40), colorectal (n=39), small bowel (n=36) and esophago-gastric (n=19). Pre-operative serum albumin was identified to be single most statistically significant pre-operative variable predicting post-operative complication of Clavien-Dindo severity grade III and above. The ROC curve of the serum albumin level predicting the severe post-operative complication suggested optimal cut off value of 3.1 gm/dl (AUC=0.76; 5% CI=0.64-0.87; p<0.001). Linear regression analysis of serum albumin level predicting the severe post-operative complication suggested good correlation with (r2=0.133; b=0.689; p<0.001). Further analysis of serum albumin level in predicting the length of ICU and the hospital stays suggested a significant negative correlation with both of these dependent outcome variables. The serum albumin level correlated inversely with the length of ICU stay and hospitalization.Conclusions: Low pre-operative albumin (serum level <3.1 gm/dl) in patients undergoing major gastrointestinal surgery predicts severe post-operative complications, prolonged ICU and hospital stays.