This paper deals with successful co-deposition of Ni-Fe/Si3N4 nanocomposites applying various current densities (0.5-3.0 A dm(-2)) from a sulfamate-DMF (N,N-dimethylformamide) bath containing different concentration of Si3N4 nanoparticles. The nanocomposits have been characterized by powder X-ray diffraction, scanning electron microscopy, transmission electron microscopy, atomic force microscopy and Energy Dispersive X-ray Analysis. The microhardness, magnetic and electrical properties along with thermal stability has been evaluated. A maximum of 13.6 wt% Si3N4 particles is incorporated in the metallic matrix from 10 g/L bath load of the ceramic particles. The matrix has face-centred-cubic structure. The crystallite size of the nanocomposites is found in the range of 8-13 nm while the strain values ranged between 0.0081 and 0.01. The magnetic measurement reveals superparamagnetic character of the coatings. Occlusion of nano-Si3N4 renders superior hardness to the matrix metal. The hydrogen content in the coatings is minimal, i.e. nearly 6 ppm, which does not cause any adverse effect on the micro-and crystallographic structure of the composites. (C) 2014 The Electrochemical Society. All rights reserved.