Abstract Certain molecular solids, especially polymeric ones, can exhibit high dielectric constants and electronic conductivity. They are normally non-crystalline. The highly conjugated polymer chosen for this study is representative of a large class of similar highly stable, carrier rich, organic solids. Dielectric constants of 5000 and higher were observed. Conductivity and permittivity were studied over a range of frequencies (dc to 300 kHz) and temperatures (68.5 to 296°K). The dc conduction is electronic, with an activation energy of 0.095 eV. The ac conduction follows a T 1 4 relation, and increases with frequency. Transport is by thermally assisted hopping (tunneling) between chains and along the chains. Thermally activated motion of the carriers within the chains was followed by comparing the in-phase and out-of-phase permittivities throughout the temperature and frequency range studied.