Electrical and morphological properties of Polyaniline (PANI) filled with various mass fractions of manganese chloride (MnCl2) synthesized in aqueous hydrochloric acid (HCl) medium using ammonium persulphate as an oxidant were investigated. The sample morphology was characterized by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). Significant changes were observed in the morphology of the samples depending on the filler level. The direct current (dc) and alternating current (ac) electrical properties were investigated as a function of temperature. The dc conductivity decreased 72% with 10% filler level whereas ac conductivity has shown a 120% increase with 6% filler level at room temperature. It is shown that the alternating charge transport mechanism of the unfilled and filled polyaniline samples is consistent with correlated barrier hopping (CBH) model. Imaginary (M '') parts of electric modulus exhibited temperature-dependent dielectric relaxation behavior for both filled and unfilled PANI samples. POLYM. ENG. SCI., 51:617-623, 2011. (C) 2010 Society of Plastics Engineers