In this study, synthesis of conducting polyaniline (PAn)/potassium-feldspar (K-feldspar) composites, having various amounts of PAn, was carried out using (NH4)(2)S2O8 as oxidizing agent. The conducting composites were characterized by a series of techniques namely: Fourier transform-infrared, X-ray diffraction, scanning electron microscopy, thermogravimetry analysis, two-probe conductivity, magnetic susceptibility, and particle size measurements. For electrorheological (ER) measurements, the conductivities of the composites were reduced by a dedoping process. A series of suspensions were prepared in silicone oil, having various volume fractions, and then subjected to colloidal stability, flow rate, ER and creep-recovery tests. Enhancement in the electric field-induced viscosities and shear thinning non-Newtonian viscoelastic behavior was observed for all the composite materials studied. Recoverable viscoelastic deformations were detected from the creep and creep-recovery tests under externally applied electric field thus; they were classified as smart materials.