Hexagonal BaTiO3/Ni0.8Zn0.2Fe2O4 (BT/NZO) composites were synthesized by solid-state reaction method. Phase composition, microstructure, dielectric and magnetic properties of the composites were investigated. The BT/NZO composites had giant dielectric constants and very high permeabilities simultaneously. According to Cole-Cole plots, the composites showed a polydispersive nature of the Maxwell-Wagner relaxation. The forming mechanism of hexagonal BaTiO3 in the composites was also investigated. (c) 2012 Elsevier B.V. All rights reserved.