© 2019 Optical Society of America. We report on the characterization of energy transfer in iron-chromium co-doped ZnSe middle-infrared laser crystals. The room temperature kinetics of the Fe:Cr:ZnSe sample under excitation of chromium ion at 1560 nm shows that energy transfer in Fe-Cr centers could be as fast as 290 ns. This rate is close to the non-radiative relaxation rate of Fe2+ ions in this host. The analysis of energy transfer rate in Cr-Cr; Fe-Fe and Cr-Fe pairs based on the resonance dipole-dipole interaction showed that energy transfer rate could be as fast as 109 s-1.