This work investigates the synthesis of Al-substituted nickel ferrite by powder conventional method with different Al contents with x=0.0, 0.1, 0.2, 0.3, 0.4 and 0.5 (NiAl x Fe 2−x O 4 ). X-ray diffraction, scanning electron microscopy, vibrating sample magnetometry and measurement of inductance–capacitance–resistance were carried out at room temperature to study the structural, magnetic and electrical properties. The structural analysis reveals that the lattice parameter and the grain size decrease as the Al content increases. The magnetic and electrical measurements show that the saturation magnetization, Curie point, coercivity and equivalent series resistance decrease by increasing the Al content.