Nanostructured Fe-6P-1.7C powders were obtained by mechanical alloying in a planetary ball mill. Morphological, microstructural and structural changes during the milling process were followed by scanning electron microscopy, X-ray diffraction and Fe-57 Mossbauer spectrometry. The crystallite size refinement to the nanometer scale (5-8) nm is accompanied by an increase in the internal strain. The nanocrystalline structure distortion is evidenced by the lattice parameter changes of the milling products. The hexagonal Fe2P Phosphide is formed within 6 h of milling, while the tetragonal Fe3P and orthorhombic Fe3C phases appear after 12 h of milling. A mixture of Fe3P phosphicle, Fe3C carbide and alpha-Fe(C, P) solid solution is obtained on further milling time. (C) 2009 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.