Magnetic behavior, microstructural evolution, and amorphization studies of Fe42Ni28Zr8Ta2B10C10 alloy, synthetized by mechanical alloying, were investigated. The non-equilibrium microstructure originated from a grain size reduction to about 2.5 nm indicated by X-ray diffraction and the introduction of internal strain up to 3.8%. The results showed that as the milling time increased the amorphous phase became dominant and reached about 92 wt.% at 176 h. The magnetic measurements which were obtained by vibrating sample magnetometer, showed an increase in saturation magnetization up to 12 h and then a decrease until 66 h followed by a slow increase. Simultaneously, the coercivity increased, decreased and finally reached a constant level of about 24 Oe. The value of coercivity obtained in the present study is less than the values reported for the widely investigated mechanically alloyed Fe-Ni-Zr-B alloys, which shows this alloy is a very good soft magnet. (C) 2013 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.