BACKGROUND The objective of this study was to compare the efficacy, safety and tolerability of intravenous iron sucrose with that of oral ferrous fumarate in iron deficiency anemia during 14 to 34 weeks of pregnancy. METHODS A randomized controlled trial was performed involving 112 patients attending the antenatal clinic at Shri B.M.Patil Medical college Hospital, Bijapur from October 2011 to August 2012,with hemoglobin levels between 70-110 g/L and serum ferritin of < 15 ng/ml. In the intravenous group,200 mg of iron sucrose was administered in 100 ml 0.9% sodium chloride per day. Participants in the oral group were given 200 mg of ferrous fumarate per day. The primary outcome measures for the trial, haemoglobin and serum ferritin levels were measured after 4 weeks. Statistical significance was assessed using Student's t-test. RESULTS The change in haemoglobin in women receiving intravenous iron was higher than with oral ferrous fumarate 22 ± 11.5 g/L vs 12 ± 9 g/L (p < 0.0001).Similarly the change of serum ferritin was significantly higher in women receiving intravenous iron compared to oral iron. 55% participants in the intravenous group had an improvement in haemoglobin more than 20 g/L compared to only 11% of the oral therapy group.48% of patients in I.V group showed increase in ferritin level between 51 to 100 ng/ml in comparison to only 3.5% in oral group. Intravenous iron sucrose is an effective in correction of anemia in pregnancy or iron store depletion. CONCLUSIONS Intravenous iron sucrose is more effective than 200 mg a day ferrous fumarate in increasing maternal iron stores. BACKGROUND The trial registration number is CTRI/2016/12/007552 registered in Clinical Trial Registry India on 8/12/2016. It is a retrospectively registered trial.