Mechanical alloying was used in order to synthesize nanocrystallized ZnSb powder. It has been shown that after 3 h of milling and with an excess of zinc in the mixture of Zn + Sb powder, the ZnSb phase was obtained with crystallites size of 40 nm. This powder was characterized by X-ray diffraction using Rietveld refinement and differential thermal analysis before being sintered by Spark Plasma Sintering. We also present thermoelectric properties of ZnSb and a comparison is made with a solidified ingot of ZnSb. Thanks to our method of synthesis, the electrical properties (power factor) of ZnSb are stable in the temperatures range (300-700 K) and very close to the ones of Zn4Sb3 which is the best thermoelectric material so far in the Zn-Sb system. (C) 2016 Elsevier B.V. All rights reserved.