ZnSe layers (1–2 μm thick) have been grown by molecular beam epitaxy on both (111) and (100) oriented ZnSe substrates. The layers were grown on atomically clean, single‐crystalline ZnSe surfaces preparedinsituby an Argon‐ion sputtering/annealing process. Homoepitaxial ZnSe layers grown on (111) ZnSe exhibited microtwinning as indicated by reflection high energy electron diffraction (RHEED) observations together with zero detectable excitonic photoluminescence emission. In contrast, layers grown on (100) ZnSe had smooth surfaces, indicated by a streaky RHEED pattern, and exhibited strong 4.2 K excitonic emission at 2.7980 eV (I0α). This can be contrasted with the Ga‐bound excitonic emission at 2.7972 eV (IGa20) observed from layers grown on (100) GaAs substrates.