In this study, vanadium doped NiFe2O4 was produced by using mixed oxide technique. The NiFe2-xVxO4 composition was synthesized and x was selected as 0.1, 0.2 and 0.3, respectively. The single-phase Ni ferrite was produced after sintering at 1100 degrees C for 4h. X-Ray diffraction (XRD), scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) were performed for structural analysis. The results of the structural analysis indicated that the second phase did not form in NiFe2-xVxO4. Additionally, the polyaniline-vanadium doped NiFe2O4 composites were produced by hot pressing using the compositions of NiFe1.9V0.1O4.1, NiFe1.8V0.2O4.2, NiFe1.7V0.3O4.3, and aniline. The weight ratios of vanadium-doped nickel ferrite and aniline were 1:1 and 1:3, respectively. Epoxy resin was used to produce microwave-absorbing composites. The fabricated composites were characterized by using Fourier transform infrared spectroscopy (FTIR). Furthermore, the magnetic properties of the fabricated composites were investigated by using a vibrating sample magnetometer (VSM). The microwave absorbing performances of the polyaniline-NiFe2O4: V composites were investigated by reflectivity in 0-8 GHz, using a two-port vector network analyzer. A minimum of -42.17 dB reflection performance was obtained in 7.02 GHz at the thickness of 2.0 mm. This reflection performance can be modulated simply by controlling the content of polyaniline in the samples for the required frequency bands.