Hybrid iron-containing nanocomposite materials based on polyphenoxazine (PPOA) were synthesized for the first time via chemical transformations of PPOA in the presence of iron(III) salt (FeCl3·6H2O, Fe(NO3)3·6H2O or Fe(CH3COCH=C(CH3)O)3) in an inert atmosphere under IR radiation in the temperature range of 350–600 °С. The developed hybrid nanocomposites were characterized by means of FTIR spectroscopy, X-ray diffraction (XRD), transmission (TEM) and scanning (SEM) electron microscopy, X-Ray fluorescence spectroscopy (XRF), Inductively coupled plasma atomic emission spectroscopy (ICP-AES), atomic absorption spectrometry (AAS), elemental analysis, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and magnetometry. The dependence of phase composition, magnetic and thermal properties of hybrid nanocomposites, as well as the size and shape of nanoparticles on synthesis temperature, Fe concentration and the nature of iron(III) salt was demonstrated.