NiCuZn ferrite nanopowders and polycrystalline bulk samples were prepared by wet chemical (citrate) method followed by sintering at temperatures lower than those for conventional solid‐state ceramic route. The citrate method results in nanopowders. The addition of copper promotes sintering, and results in grain‐growth during sintering, even at a low temperature. Composite thick films of desired thickness were prepared by die casting the ferrite mixed with a polymer in different weight ratios. The dielectric properties of the polycrystalline NiCuZn ferrite and their composite thick films were investigated at radio‐ and X‐band microwave frequencies. Dielectric and magnetic losses are estimated to be appreciably low, even at microwave frequencies.