Abstract Soft Mg–Ni–Zn–Cu spinel ferrites having general chemical formula Ni x Mg 0.5− x Cu 0.1Zn 0.4Fe 2O 4 (where x = 0.1, 0.2, 0.3, 0.4 and 0.5) were prepared by standard double sintering ceramic method. The samples were characterized by X-ray diffraction at room temperature. The X-ray diffraction (XRD) study revealed that lattice parameter decreases with increase in Ni content, resulting in a reduction in lattice strain. The electrical and magnetic properties of the synthesized ferrites have been investigated as a function of temperature. The variation of initial permeability and AC susceptibility with temperature exhibits normal ferrimagnetic behavior. The variation of initial permeability with frequency is studied. The Curie temperature ( T C) in the present work was determined from initial permeability and AC susceptibility. The Curie temperature increases with Ni content.