This study reports on structural, thermal and dielectric properties of Polypyrrole (PPy) and Polypyrrole/copper(II) acetylacetonate composites. Interaction mechanisms between polymer and metal ions have been determined by Fourier transform infrared (FT-IR), nuclear magnetic resonance (NMR) and atomic absorption spectroscopy (AAS). Differential scanning calorimetry (DSC) and thermo-gravimetric analysis (TGA) have shown that whilst doping process does not influence PPy cold crystallisation temperature substantially, it does have a relatively higher influence on glass transition and degradation temperatures. Different microstructures on the surface morphology have been observed depending on the doping level through the use of scanning electron microscopy (SEM). Temperature dependent dielectric measurements have shown that doping process causes a relatively monotonic increase on the real dielectric constant of PPy at high frequencies when compared to low frequencies and such increase was found to be up to 105% for maximum doping level at 1 MHz frequency. Two different frequency regions in the frequency dependent conductivity have been observed under the power law for PPy and its composites. The charge transfer mechanism can be explained via correlated barrier hoping (CBH) model. (C) 2012 Elsevier B.V. All rights reserved.