MMT Clay was modified by replacement of Na+ with anilinium ion (An+) followed by chemical oxidation with ammonium persulfate in order to produce polyaniline in a rigid structure. This MMT-Pani composite was, then, tested as conducting filler for polystyrene films, processed in a Haake torque rheometer and hot pressed. MMT-Pani filler and PS/MMT-Pani nanocomposites were characterized by XDR, FT-IR, UV-vis, TG and DSC, showing Pani intercalation inside the clay platelets and improved interactions of the conducting polymers with clay. Ac and Dc electrical conductivity of fillers and nanocomposites were analised by two probe methodology and electrochemical impedance spectroscopy (EIS), respectively. Pani alone presented a high electrical conductivity, whereas the presence of the insulanting clay affects all electrical conducting mechanism. The morphology of the nanocomposites were analysed by SEM and TEM and showed improved clay exfoliation when higher quantities of MMT-Pani filler were added.