The electromagnetic interference (EMI) shielding properties of polypyrrole/barium ferrite/tantalum pentoxide nanocomposite were studied in the X-band frequency range from 8.2 GHz to 12.4 GHz.The nanocomposites were chemically synthesized at room temperature and then characterized by various techniques.The dielectric material parameters were calculated based on the experimental scattering parameters using Nicholson-Ross and Weir algorithms.The synthesized nanocomposites demonstrated that the shielding effectiveness up to 50 dB depended upon the dielectric loss and weight fraction of ferrite and Ta2O5 in the polymer matrix.