<p>Antenatal anaemia affects 48% of pregnant women in South Asia. In Bangladesh, the standard of care is oral iron and folic acid supplementation, but access and adherence are poor. Intravenous iron is an alternative treatment that deliver high dose of iron in a single short infusion and is commonly used in high-income countries. A demonstration project will be conducted to test the real-world feasibility and acceptability of implementing an intravenous iron intervention to treat pregnant women with moderate and severe anaemia in the primary healthcare setting of Bangladesh. This protocol paper outlines the development, implementation, and evaluation of an intravenous iron intervention. The demonstration project consists of three phases, supported by implementation science frameworks: (1) a formative phase involving a review, qualitative research, and readiness assessment; (2) the development and implementation of care pathways and strategies using a participatory research approach; and (3) a process evaluation of care pathways and strategies involving qualitative and quantitative assessment of the costs, processes and contextual factors affecting its implementation. Intravenous iron presents a novel opportunity to reduce antenatal anaemia in low-and-middle income countries. The demonstration project will ascertain whether an intravenous iron intervention can be effectively introduced into routine antenatal care and the extent to which it is considered an acceptable treatment by pregnant women, healthcare providers, and policymakers. If successful, insights into the care pathways and costs will provide guidance for integrating intravenous iron in the primary healthcare system of Bangladesh and other low-and-middle income countries.</p>