Poly (vinyl alcohol)—Cellulose acetate (PVA/CA) blend polymer doped with Ammonium thiocyanate salt in the presence of Ethylene Carbonate (EC) as a plasticizer were prepared by simple solution casting technique. PVA/CA blend ratio was first optimized for highest conductivity value (3.63 × 10−6 S/cm). The ionic conductivity of PVA/CA blend was further enhanced by adding 0.5 mol wt% NH4SCN and 0.3 mol wt% EC. The value of the ionic conductivity at room temperature was increased to 7.7 × 10−4 S/cm. AC impedance spectroscopy studies were used to calculate ionic conductivity values. Fourier Transform— Infrared Spectroscopy measurements revealed the existence of blending and salt complexation with host polymer. Activation energy and relaxation time were observed for the prepared plasticized membranes using Arrhenius plot and loss tangent spectra. The ionic conductivity at room temperature was further increased to the value of 2.1 × 10−3 S/cm by the addition of nano-alumina particles. © Springer International Publishing Switzerland 2017.