The nanorods of cadmium selenide (CdSe) have been synthesized by soft chemical route using mercapto ethanol as a capping agent. The sample forms a rod like shape, confirmed by transmission electron microscope (TEM) measurement. Impedance spectroscopy is applied to investigate the dielectric relaxation of the sample at a various temperature region with varying frequency range. Grain and grain boundary effects both are present in the complex impedance plane plot and is analyzed by an electrical equivalent circuit consisting of a resistance and a constant-phase element. Dielectric relaxation mechanism shows peak positions in the imaginary parts of the spectra and that is analyzed by Cole–Cole model. The temperature-dependent relaxation times obeys Arrhenius law having activation energy of 0.391 eV, which indicates that polaron hopping is responsible for conduction or dielectric relaxation in this material. The presence of two plateaus in the frequency-dependent conductivity spectra follows double-power law.