|Abstract||Germanium dioxide (GeO2) nanoparticles reinforced poly(vinyl chloride) (PVC) and poly(methyl methacrylate) (PMMA) blend nanocomposite films were prepared using solution casting technique. The PVC/PMMA/GeO2 nanocomposite films were characterized by FTIR�Fourier transform infrared spectroscopy, XRD�X-ray diffraction and TGA�thermogravimetric analysis. The morphological and structural characteristics were examined using POM�polarized optical microscopy, SEM�scanning electron microscopy and AFM�atomic force microscopy. The dielectric properties and the electromagnetic interference (EMI) shielding effectiveness of these nanocomposite films were also studied. The EMI shielding properties were studied in the broadband microwave region of X (8�12�GHz) and Ku band (12�18�GHz). From SEM micrographs, the porous network was unfolded that enriches the absorption behaviour. The EMI shielding effectiveness of ? 17.1 dB was observed for PVC/PMMA/GeO2 nanocomposite film with 10 wt % GeO2 loading and the nanocomposite film with 8�wt% of GeO2 loading showed the potential to attenuate electromagnetic waves through absorption up to 75%. Hence, the EMI shielding results demonstrate that the PVC/PMMA/GeO2 nanocomposite films can be used as an absorption dominating shielding materials. � 2018, Springer Science+Business Media, LLC, part of Springer Nature.