Background: PNI is significantly associated with surgical outcomes; however, the association between PNI and intraoperative transfusions is unknown. Methods: This study retrospectively analyzed 1065 patients who underwent hepatectomy. We divided patients into two groups according to the PNI (<44 and >44) and compared their transfusion rates and surgical outcomes. We performed multivariate logistic and Cox regression analysis to determine risk factors for transfusion and the 5-year survival. Additionally, we found the net reclassification index (NRI) to validate the discriminatory power of PNI. Results: The PNI <44 group had higher transfusion rates (adjusted odds ratio [OR]: 2.20, 95%CI: 1.06–4.60, p = 0.035) and poor surgical outcomes, such as post hepatectomy liver failure (adjusted [OR]: 3.02, 95%CI: 1.87–4.87, p < 0.001), and low 5-year survival (adjusted OR: 1.68, 95%CI: 1.17–2.24, p < 0.001). On multivariate analysis, PNI <44, age, hemoglobin, operation time, synthetic colloid use, and laparoscopic surgery were risk factors for intraoperative transfusion. On Cox regression analysis, PNI <44, MELD score, TNM staging, synthetic colloid use, and transfusion were associated with poorer 5-year survival. NRI analysis showed significant improvement in the predictive power of PNI for transfusion (p = 0.002) and 5-year survival (p = 0.004). Conclusions: Preoperative PNI <44 was significantly associated with higher transfusion rates and surgical outcomes.