NiWO4 nanostructures doped with different ratios of Eu3+ have been prepared by a chemical precipitation method. The influence of Eu3+ on NiWO4 nanostructures were characterized using X-ray diffraction (XRD), UV–visible diffuse reflectance spectra, scanning electron microscopy (SEM), Transmission electron microscopy (TEM) and Raman. XRD patterns display that the samples crystallize to monoclinic wolframite structure. SEM images reveal that the particles are well uniformly dispersed with average particle size lies around 40–50 nm. Third-order nonlinear optical properties were studied by a Z-scan technique at 532 nm using continuous wave diode pumped Nd:YAG laser. Open and closed aperture results reveal the nanostructures to possess reverse saturation absorption and negative nonlinear refraction. The calculated absorption coefficients (β), imaginary part of third-order susceptibilities Imχ(3) are in the order of 10–6(cm/W) and 10–7 esu. These results indicated that the synthesized nanostructures could be promising materials for optical device applications. © 2021, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.