Laser action in undoped, nitrogen and chlorine doped ZnSe epitaxial layer has been achieved and investigated at pulse optical excitation by N2 laser radiation with a frequency of 1000 Hz from liquid nitrogen temperature up to near room temperature at 270 K. The highest value of ZnSe laser energy and power were E = 5×10−8 J and P = 5 W at Iexc = 800 kW/cm2. The laser line positions in doped samples ZnSe:Cl λ = 450.7 nm) and ZnSe:N λ = 451.2, 451.5, 452.0 and 455.5 nm at different excitation intensities) are shifted to the high wavelength side compared to undoped ZnSe λ = 449.8 nm). It was shown that doping ZnSe with both acceptor or donor impurities as well as using a ZnMgSSe barrier layer between the ZnSe layer and the substrate is favourable to increase PL efficiency and to decrease the laser threshold. The lowest threshold value (130 to 150 kW/cm2) was achieved in ZnSe:N grown with hydrogen carrier gas. The results obtained from measurements of the laser line positions as well as from the evaluation of the nonequilibrium carrier concentration proves that the ZnSe lasing mechanism under excitation by the N2 laser radiation is the recombination in an EHP. We found that under high excitation intensity a degradation of the excited region of the ZnSe takes place causing a decrease of the emission intensity. Under lower excitation power the PL intensity enhances during the course of irradiation.