Quaternized polysulfone with triphenylphosphonium pendant groups was investigated, as to its optical and electronic properties. Optical properties were analyzed by refractivity and transmission spectra. To obtain the optical parameters, the approach proposed by Tauc for amorphous semiconductors has been used, because of the similarity of the absorption edges. Values of pseudogap energy and Urbach energy of 3.89 eV and 168 meV, respectively, were obtained. The dielectric properties and AC-conductivity were also studied as a function of temperature and frequency. Decrease in the dielectric constant was observed with the increase in frequency and decrease in temperature. Also, quaternized polysulfone films were characterized by two relaxation processes, gamma and beta relaxation, which appear at different temperatures, depending on the pendant group. The frequency-temperature-dependent conductivity showed that conductivity increases with frequency and also that the quaternized polysulfones possess typical semiconducting properties. All parameters have been found as slightly influenced by the polymer chain structure.