Nanocrystalline InSb was prepared by mechanical alloying from equiatomic powder mixture. X-ray diffraction, energy dispersive spectroscopy and differential scanning calorimetry techniques were used to study the structural, chemical and thermal properties of the as-milled powder. Ail annealing procedure was carried out at 410 degrees C for 6 h to test thermal stability and to clarify some features showed in the calorimetry curve of as-milled sample. The main crystalline phase formed was the zinc blend InSb, but residual amorphous and minority crystalline (In2O3 and Sb) phases were also observed for mechanical alloyed and annealed samples, respectively. The structural parameters, phase fractions, average crystallite sizes and microstrains of all crystalline phases were obtained from Rietveld analyses of the X-ray patterns using the GSAS package. The results showed an increasing of the average crystallite size and reduction of microstrain with annealing. Furthermore, the DSC results suggest that the minority In2O3 and Sb phases observed in the annealed sample can be attributed to the crystallization of the amorphous component. (C) 2008 Elsevier B.V. All rights reserved.