Abstract Exciton luminescence is studied in a series of Cd 0.33Zn 0.67Te/ZnTe single quantum wells as a function of temperature. We find that the broadening of the exciton line with temperature is consistent with LO-phonon scattering. The homogeneous linewidths of the samples versus temperature are extracted by a deconvolution procedure. The average phonon coupling parameter Γ ph for these samples is found to be 15 meV. This value of Γ ph is surprisingly only 1.5 times greater than GaAs single quantum well samples and is the reason why strong exciton resonances are observed at room temperature in these Cd 0.33Zn 0.67Te materials.