This study focuses on the thermal, photo-optical and electrochemical characterization of some copoly(oxadiazole-naphthylimide)s containing tetramethyldisiloxane units. The thermal stability and glass transition temperatures of these copolymers were measured and compared with those of related polymers. The polymers were processed in very thin films having smooth surfaces, without pinholes or cracks. Upon irradiation with UV light the polymers showed photoluminescence maxima in the blue spectral range. Cyclic voltammetry was performed to obtain information about the electrochemical stability and reversibility of the redox processes of these polyimides. The HOMO and LUMO energy levels, and electrochemical and optical band gap values were calculated by using cyclic voltammetry and UV-Vis spectroscopy data, showing very good electron-injection and transport characteristics. These properties make the present polymers suitable for application in electroluminescent devices.