The roles of metal (Me) ions (Cu(II) and Cr(III)) in the morphologies and structures of hematite particles, produced from a forced hydrolysis reaction of FeCl3-HCl at various concentrations of metal ions ranging from 0 to 0.8 in the Me/(Fe + Me) atomic ratio (X-Me), were investigated by separation of the reaction into two steps: precipitation of beta-FeOOH and phase transformation from beta-FeOOH to hematite. The metal ions inhibited the particle growth of beta-FeOOH at a lower concentration region, while they promoted the particle growth at a higher concentration region with incorporation of these ions into the crystal lattice. The beta-FeOOH particles produced with metal ions exhibited high specific surface areas and microporosities. It was suggested that the phase transformation from beta-FeOOH to hematite is strongly affected by the metal ions incorporated into beta-FeOOH particles but not by those adsorbed on the particle surface.