introductionIron-deficiency anaemia is common in gynaecological oncology patients. Blood transfusions are immunosuppressive and carry immediate and long-term risks. Oral iron replacement remains the standard of care but requires prolonged treatment courses associated with gastrointestinal side effects, poor compliance and variable absorption in cancer patients. Intravenous iron has been shown to decrease the need for allogeneic blood transfusion in gynaecological oncology patients undergoing chemotherapy, but the efficacy of this treatment in the preoperative period is unknown. The goal of this pilot study is to determine the effect of intravenous ferric derisomaltose on preoperative haemoglobin in patients undergoing surgery for gynaecological malignancy. METHODS AND ANALYSIS: We will conduct a pilot single-centre, parallel-arm randomised controlled trial of intravenous ferric derisomaltose versus placebo among consenting patients with iron-deficiency anaemia having elective major surgery on the gynaecological oncology service. Patients, clinicians and outcome assessors will be blinded. The intervention consists of a single infusion of 500-1000 mg of intravenous ferric derisomaltose administered a minimum of 21 days prior to the planned operation. The primary outcome is mean preoperative haemoglobin concentration measured 0-3 days prior to surgery in patients receiving intravenous ferric derisomaltose compared with those receiving placebo. Secondary outcomes include the following: change in haemoglobin concentration, postoperative haemoglobin concentration, perioperative blood transfusion rates, patient-reported quality of life scores (Quality of Recovery 15, Modified Short Form 36 v1, EuroQol 5-dimension 5-level and Functional Assessment of Cancer Therapy - Anaemia), surgical site infection, complication rates, length of hospital stay and readmission rate. Analyses will follow intention-to-treat principles for all randomised participants. All patients will be followed up to 60 days following surgery. ETHICS AND DISSEMINATION: Ethical approval has been granted by Health Research Ethics Board of Alberta (Project ID: HREBA.CC-22-0187) and Health Canada (HC6-024-c264013). Results will be disseminated through presentation at scientific conferences, peer-reviewed publication and social and traditional media. TRIAL REGISTRATION NUMBER: NCT05407987.