Background: The aim of this study was to compare the efficacy, safety and achievement of the target hemoglobin level (Hb ≥10 g/dl) in patients with preoperative anemia due to menorrhagia who received intravenous iron sucrose compared with oral iron protein succinylate for anemia management. Methods: Seventy-six patients with Hb levels <9.0 g/dl who were scheduled to undergo surgical treatment were randomized to receive either intravenous iron sucrose (based on the calculated total iron deficit divided into 2 ampoule infusions intravenously 3 times a week, beginning 3 weeks before surgery) or oral iron (80 mg/day of oral iron protein succinylate daily). Results: The intravenous iron group had higher increases in Hb (3.0 vs. 0.8 g/dl; p < 0.0001) and ferritin levels (170.1 vs. 4.1 μg/l; p < 0.0001) than the oral iron group. Achieving the target Hb was also higher in the intravenous iron group than in the oral iron group (76.7 vs. 11.5%; p < 0.0001). There were tolerable adverse events in both groups. Conclusion: Preoperative intravenous iron sucrose administration is more effective than oral iron and is as safe as oral iron therapy in the correction of preoperative anemia due to menorrhagia.