The physicochemical properties of NZFO/f-MWCNTs composites based on 5 wt% of Ni0.5Zn0.5Fe2O4 (NZFO) nanoparticles and functionalized multi-walled carbon nanotubes (f-MWCNTs) synthesized via ex-situ method are presented. The influence of annealing on the as-received hybrids is discussed. The structural and microstructural analysis confirms the efficiency of the synthesis process. The slight redistribution of cations over tetrahedral and octahedral sites is noted by Raman and X-ray photoemission (XPS) studies. The NZFO crystallite size is almost stable over sample processing, but the presence of single particles, clusters and aggregates on the f-MWCNTs’ surface is proven. The XPS spectra comparison reveals the domination of nanotubes as designed. The deconvoluted Fe2p lines confirm the iron redistribution slightly modified by annealing. The magnetic properties analysis revealed the cluster-glass state of NZFO particles. The core-shell-like structure with a magnetic core and disordered layer is evidenced. The influence of Fe-based carbon matrix residues in all hybrids was detected.