Backgrounds: This study aims to identify the objective findings of haemoglobin (Hb) drift in patients that had a Whipple’s procedure in the last 10 years, their transfusion status intra- operatively and post-operatively, the potential factors affecting Hb drift, and the outcomes following Hb drift. Methods: A retrospective study was conducted at Northern Health, Melbourne. All adult patients who were admitted for a Whipple’s procedure from 2010 to 2020 were included and information collected retrospectively for demographics, pre-operative, operative and post-operative details. Results: A total of 103 patients were identified. The median Hb drift calculated from a Hb level at the end of operation was 27.0 g/L (IQR 18.0–34.0), and 21.4% of patients received a packed red blood cell (PRBC) transfusion during the post-operative period. Patients received a large amount of intraoperative fluid with a median of 4500mL (IQR 3400-5600). Hb drift was statistically associated with intraoperative and post-operative fluid infusion leading to concurrent issues with electrolyte imbalance and diuresis. Conclusion: Hb drift is a phenomenon that does happen in major operations such as a Whipple’s procedure, likely secondary to fluid over-resuscitation. Considering the risk of fluid overload and blood transfusion, Hb drift in the setting of fluid over-resuscitation needs to be kept in mind prior to blood transfusion to avoid unnecessary complications and wasting of other precious resources.