Growth of high‐quality ZnSe films on GaAs(100) substrates by conventional molecular‐beam epitaxy (MBE) and migration enhanced epitaxy (MEE) have been examined. We have found a self‐regulatory MEE process in the temperature range between 350 and 400 °C where a complete monolayer of ZnSe was achieved per three operational cycles of Zn+Sen. Thin films (<1 μm) grown by self‐regulatory MEE exhibited much higher structural perfection than MBE thin ZnSe films grown under closely identical conditions. The explanation for these structural differences must lie in details of how initial nucleation takes place in MBE and MEE. For thicker films (≂2 μm) no significant differences in structural or electrical properties were found for the two methods.