A solid waste material fly ash cenosphere (FAC) was nickel coated and polyaniline in situ polymerized at -30 ± 2 °C in nitrogen atmosphere. Athin film of this composite material was prepared by solution processing and surface morphology/topography was studied. High electromagnetic shielding effectiveness (SE) was obtained for this film; 59 ± 4 μmand 133 ± 4 μmfilms show an average of 38 and 60 dB SE, respectively, in the frequency range 8.2-12.4 GHz (X-band). Unlike PANI film, the SE of these composite films is high at high frequency. The presence of magneto dielectric microsphere (Ni-FAC) increases the heterogeneity of the composite film in an efficient way for EMI shielding by changing film topography and increasing ac conductivity and permeability. © 2015 IOP Publishing Ltd.