This review aims to summarize the available evidence of the effectiveness of oral iron in patients receiving dialysis. Four small randomized controlled trials (105 evaluated patients) compared oral iron supplements with placebo or no treatment; hemoglobin and ferritin levels did not differ significantly between groups at the end of the studies, while transferrin saturation levels fell in the placebo group in two studies. One trial (46 evaluated patients), comparing different ferrous iron preparations, found that hemoglobin levels and iron indices were maintained, but not increased. Another trial (54 evaluated patients) compared heme iron polypeptide with ferrous sulfate; hemoglobin and transferrin saturation levels remained stable with both agents, but ferritin levels fell with heme iron polypeptide, but not ferrous sulfate. Two observational studies found that iron supplements can maintain hemoglobin and iron indices. Oral iron supplements were poorly tolerated. These sparse data suggest that oral iron is of little or no benefit in raising hemoglobin and iron indices in patients receiving dialysis. Further data are required to determine if oral iron can maintain adequate iron indices following iron replenishment using intravenous iron supplements.