In this study we have focused our attention on the transformations of iron nanowires (Nws) encapsulated in the alumina template pores with the diameter empty set(pore) from 8 to 30 nm when the samples are stored and annealed in air at temperatures up to 600 degrees C. Using Mossbauer, XRD and SEM methods we have shown that annealing in air of Fe-0 Nw arrays in a sealed alumina matrix results in the formation of paramagnetic Fe(II) and Fe(III) compounds, most probably, in a spinel FeAl2O4 (hercynite) and (FexAl1-x)(2)O-3. The diameter of Fe-0 Nws defined the annealing temperature T-ann at which the ferromagnetic component disappeared, as well as an outcome of transformations. A decrease in the diameter empty set(pore) results in the disappearance of ferromagnetic iron at lower T-ann and in a prevailing formation of a (FexAl1-x)(2)O-3 component. The obtained results were used to clear up a mechanism of these transformations. (C) 2008 Elsevier B.V. All rights reserved.