Photoluminescence properties of ZnTe-ZnS strained layer superlattices (SLS) grown on GaAs (100) substrates by metal-organic chemical vapor deposition (MOCVD) at atmospheric pressure (AP) were studied. The interband transitions of the superlattices due to free electron-hole recombination were observed at 77K. At higher excess carrier densities, the recombination of subbands lying higher in energy becomes increasingly important. Energy band structures of the ZnTe-ZnS SLSs were calculated by using the Kronig-Penney model and taking into account the strain effects due to the lattice mismatches between the materials. The structure dependence of the PL is explained by the theoretical calculation fitted to the experimental data.