The selective-area growth of ZnSe is performed by molecular beam epitaxy on oxide-masked GaAs(0 0 1) substrates. Single-crystalline layers are obtained on a bare surface of the GaAs substrate, while poly-crystalline layers are deposited on an SiO2-covered region. The growth rate of a single-crystalline layer is faster than that of a poly-crystalline layer at least up to a substrate temperature of 340 degrees C. The difference in growth rate increases with increasing the substrate temperature. The low-temperature photoluminescence of a single-crystalline layer shows dominant excitonic emission.