As doping material rare-earth elements are widely used changing considerably semiconductor’s optical, electrical and radiative properties. This work describes influence of the gadolinium on radiative and optical properties of the ZnSe. Single crystals were grown by physical transport method and were doped during growth. GdSe compound were doping source. X-ray diffraction, photoluminescent properties and optical transmission in the wide spectral range were analyzed. Radiative bands corresponded to intracentered transition of the doping impurity have not been registered. Gadolinium ions contribute to the background impurity activation creating radiative transitions from conduction band to the Cu2+ levels and intracentered transitions of the Cr2+ ions. However, edge band intensity has strong dependence from impurity concentration and is very less to the intensity of the undoped ZnSe. Edge band decay changes from bimolecular to the monomolecular recombination. Optical transparency is decreasing, but fundamental absorption band position is stable. X-ray diffraction shows that single crystals have zinc blende crystal structure and there is no GdSe phase formation. However, crystalline grain calculus reveals its growth with the impurity increase. Weak shift of the peak direction (331) is detected, while peaks directions (311) and (111) are stable. Hence, complex analysis of the ZnSe:Gd has determined that the Gd impurity is present in the single crystals and creates associates. Composition of these associates could be background impurities copper and chromium, which activates with crystal’s free energy captured by gadolinium ions.