•We have synthesized large sized and high-quality single crystals of NiWO4.•Magnetic anisotropy was studied on single crystals by magnetic susceptibility.•Magnetization was measured in magnetic fields up to 30T and the spin-flop transition was observed in the vicinity of 17.5T. NiWO4 exhibits a spin chain structure built by magnetic Ni2+ ions, which may be considered as a one dimensional S=1 system. In this work, large-sized single crystals of NiWO4 were successfully synthesized by a flux method and the crystal quality was confirmed by X-ray diffraction. Magnetic properties of obtained single crystals were studied by means of magnetic susceptibility and high field magnetization along crystallographic axes. The results demonstrate that NiWO4 is highly magnetic anisotropic and possesses a three-dimensional long range ordering below 60K, where a spin flop transition can be observed at 17.5T in applied magnetic fields along the magnetic easy axis (c-axis).