Nanoparticles of Zinc substituted Cobalt ferrite powders having general formula ZnxCo1-xFe2O4 (x = 0, 0.25, 0.5, 0.75, 1.0) have been produced by using analytical grade nitrates and hexadecyltrimethylammonium bromide (CTAB) as structure directing reagent via Chemical co-precipitation method. The structure and morphology of prepared polycrystalline ferrite nanoparticles were investigated by X-ray diffraction (XRD), Fourier Transform Infrared Radiation (FTIR) and Scanning electron microscopy (SEM) respectively. Thermogravimetric differential analysis (TG/DTA) technique gives information about ferrite phase formation occurs beyond 450 ºC. The XRD analysis confirms the establishment of the cubic spinel structure with the presence of minor secondary phase of α-Fe2O3 (hematite) at a calcination temperature of 650 ºC. The polycrystalline mixed zinc cobalt ferrite nanoparticles showed a dual phase and crystallite size lies in the range 6-11 nm. FE-SEM microstructure shows the nearly spherical polycrystalline nanoparticles with a particle size in between 0.11-0.20 µm. The FT-IR spectra display two significant strong absorption bands nearby in the range of 400 cm-1 and 600 cm-1 on the tetrahedral and octahedral sites respectively. Copyright © 2018 VBRI Press.