Conductive polymer composites are at the forefront of composites science research because of the huge number of applications that have been developed around their interesting and unique properties. The present article is focused on the fabrication of natural rubber/polyaniline (NR/PANI) compounds for electromagnetic wave shielding applications at microwave frequency. Their microstructures were examined by means of scanning electron microscopy and thermogravimetric analyses. The as-fabricated NR/PANI composite was mechanically characterized to investigate the effect of dispersion of PANI on NR matrix composite. The dielectric spectroscopy, absorption loss, and reflection loss of NR/PANI composite in the frequency range from 1 to 12 GHz have been performed. The total electromagnetic interference shielding effectiveness by absorption and reflection loss depends on PANI content in the composite. Results show that the NR/PANI composite represents a new class of conducting lightweight material that makes the NR/PANI with good electromagnetic shielding effectiveness that is suitable for use in industrial application such as electronic conducting composite in polymer package and for radar absorbing materials.