In this study, we develop an experimental procedure to synthesize hematite nanoparticles by hydrothermal decomposition of Fe-EDTA complex in the presence of hydrogen peroxide, starting from ferric ammonium sulfate and Na4 EDTA as main precursors. The product was investigated by X-ray diffraction, scaning electron microscopy, dispersive X-ray spectroscopy, magnetic measurements, and UV-vis optical absorption measurements. The size of nanoparticles was determined to be 42nm evaluated by XRD patterns using the Scherrer equation. This method allowed the formation of pure hematite nanoparticles with good and stable crystallographic characteristics. This procedure can be an effective method for synthesizing hematite nanoparticles exhibiting good crystallinity, stoichiometry, magnetic, and optical band gap properties. A possible mechanism for the formation of hematite nanocrystals was suggested.