We have found for the first time that Cu 3Se 2 nanowired products encased inside the alumina pores by electrodeposition demonstrate the promising nonlinear optical properties in UV–vis–NIR spectra region. Furthermore, the annealing of these products results in the formation of Cu 2− x Se with x depending on the annealing temperature. Optical nonlinearities of as-grown and thermally treated copper selenide nanowire arrays were evidenced using the standard open-aperture Z-scan and laser pump-probe techniques.