A ternary composite, based on the M-type hexagonal barium ferrite, BaFe12O19, conducting polymer, polyaniline (PANI), carbon allotrope, and multi-walled carbon nanotube (MWCNT), was prepared through a facile in-situ polymerization process. The structural properties of the synthesized composites were characterized through XRD and FESEM analysis. PANI particles were found to be able to coat on BaFe12O19 and MWCNT surfaces. The increased MWCNT wt loading within the composite resulted in the increase of the electrical conductivity with values as high as 2.0320 S/m for sample PBM5 (25wt MWCNT). The composite inherited the salient properties of its respective components to achieve optimum values of shielding effectiveness. The highest value of SEA recorded was 42.37 dB at 17.60 GHz. The significantly larger magnitudes of SEA than SER suggest that the mechanism of shielding for all synthesized composites are through absorption. © 2016, Electromagnetics Academy. All rights reserved.