This paper describes molecular beam epitaxial growth of PbTe/CdTe quantum wells on (100)-oriented GaAs substrates and characterization of their photoluminescence spectra. Despite of the differences in crystal structure and thermal expansion coefficient between PbTe and CdTe, an intense mid-infrared emission was observed even at higher temperatures than 300K. The energy of the emission peak showed blue shift with decreasing well width and had a positive dependence on temperature in agreement with that of bulk PbTe, indicating that the emission resulted from electron-hole recombination in a type I quantum well. Multiple peaks, however, were found in the PL spectra, and analysis of the temperature dependence of PL peak energy revealed that the thermal mismatch between CdTe and PbTe promoted the peak separation. A PbTe/CdTe double quantum well showed a higher efficiency of the PL emission. These results indicate a promising application of this heterosystem to cleaved-edge cavity laser diodes operating at room temperature.