The temperature dependence of the luminescence of a CdTe/Cd0.6Mg0.4Te quantum well (QW) was investigated in the temperature range 5-200 K. It was found that under under-barrier excitation this dependence is characterized by two nonradiative recombination channels with activation energies of 0.01 and 0.037 eV. Under above-barrier excitation, a feature appears in the temperature dependence of the QW luminescence intensity, associated with exciton delocalization in the Cd0.6Mg0.4Te barrier. Nonradiative recombination in the barrier is characterized by two activation energies: 0.0065 and 0.046 eV. A model is proposed that describes the temperature effect on the luminescence intensity of the QW and barrier, taking into account exciton delocalization in the barrier and their trapping at nonradiative recombination centers. Keywords: II-VI semiconductors, heterostructures, quantum wells, luminescence, excitation transfer.