The ZnFe2O4 ferrite nanoparticle and nanofiber were synthesized by electrospinning method. The phase composition, morphology, magnetic and electromagnetic properties were analyzed. The results showed that both the samples exhibited a pure phase of spinel type ferrite. The ZnFe2O4 ferrite nanoparticle was aggregated, while the ZnFe2O4 ferrite nanofiber performed the homogeneous nano-fibrous shape as well as single-particle-chain structure. The magnetic analysis indicated that the ZnFe2O4 ferrite nanofiber showed ferromagnetic behaviour. Moreover, the dielectric loss and magnetic loss properties of ZnFe2O4 ferrite nanofiber were both enhanced due to its better dipole polarization, interfacial polarization and shape anisotropy. Display omitted •The ZnFe2O4 ferrite nanoparticle and nanofiber were synthesized by the electrospinning method.•The ZnFe2O4 ferrite nanofiber performed the homogeneous nano-fibrous shape as well as single-particle-chain structure.•The ZnFe2O4 ferrite nanofiber behaved as the ferromagnetic property.•The dielectric loss and magnetic loss properties of ZnFe2O4 ferrite nanofiber were both enhanced.