Nickel ferrite (NiFe₂O₄) nanoparticles were synthesized using sol-gel method and the powdered samples were sintered at 100°C and 200°C. X-ray Diffraction (XRD) patterns were used to determine the structure of nickel ferrite nanoparticles. Obtained the lattice parameter from the XRD data and calculated the particle size using Debye- Sherrer formula. The details of the surface morphology of NiFe2O4 nanoparticles were studied by Scanning Electron Microscopic (SEM) analysis. The work aims at the investigation of the dielectric properties such as dielectric loss and permittivity of Nickel ferrite nanoparticles at various frequencies and temperatures. In addition, the ac conductivity of the nickel ferrite nanoparticles was studied.