OBJECTIVE: The objective of the study was to evaluate the efficacy, safety, and tolerability of intravenous ferric carboxymaltose, compared with oral ferrous sulfate in women with postpartum anemia. STUDY DESIGN: In a multicenter, randomized, controlled study, 291 women less than 10 days after delivery with hemoglobin 10 g/dL or less were randomized to receive ferric carboxymaltose (n = 143) 1000 mg or less intravenously over 15 minutes or less, repeated weekly to a calculated replacement dose (maximum 2500 mg) or ferrous sulfate (n = 148) 325 mg orally thrice daily for 6 weeks. RESULTS: Ferric carboxymaltose-treated subjects were significantly more likely to: (1) achieve a hemoglobin greater than 12 g/dL in a shorter time period with a sustained hemoglobin greater than 12 g/dL at day 42, (2) achieve hemoglobin rise 3 g/dL or greater more quickly, and (3) attain higher serum transferrin saturation and ferritin levels. Drug-related adverse events occurred less frequently with ferric carboxymaltose. CONCLUSION: Intravenous ferric carboxymaltose was safe and well tolerated with an efficacy superior to oral ferrous sulfate in the treatment of postpartum iron deficiency anemia.