Background/Aim: Recently, a decrease in serum zinc levels and the need for zinc preparations have been reported in the perioperative period of gastrointestinal surgery. In this study, we examined treatment outcomes among patients supplemented with zinc after pancreaticoduodenectomy (PD) and evaluated the significance of zinc replacement therapy. Patients and Methods: From June 2020 to April 2021, 56 patients who received zinc acetate hydrate (50 mg/day) from postoperative day 3 after PD in our department were retrospectively reviewed. Patients' characteristics and preoperative as well as postoperative data, including serum zinc levels and surgical results at 1 month were reviewed. Results: Preoperative zinc deficiency was present in 86.1% (46/56) of the patients. Moreover, despite zinc supplementation, 17.8% (10/56) of patients had postoperative zinc deficiency. A comparison between the low zinc level group (Zn <80 μg/dl) and the normal zinc level group (Zn ≥80 μg/dl) after surgery showed siginificant differences among patients with malignant diseases (vs. benign diseases, p=0.044), those undergoing open surgery (vs. minimally invasive surgery, p=0.036), and those with intraoperative blood loss ≥346 ml (vs. <346 ml: p=0.041) in the univariate analysis. Multivariate analysis revealed that zinc deficiency was significantly associated with open surgery [odds ratio (OR)=15.885, 95% confidence interval (CI)=1. 77-142.01, p=0.013] and intraoperative blood loss (OR=9.329, p=0.016). Conclusion: In patients undergoing open PD for pancreatic cancer, zinc preparations of 50 mg may not be sufficient and further supplementation may be necessary.