ZnTe nanowires were grown by molecular beam epitaxy on GaAs substrates of three different orientations: (100), (110), and (111)B. The catalyst droplets were produced through in situ annealing of a previously deposited Au layer and by forming the eutectic alloy with Ga from the substrate. The influence of substrate orientation and growth parameters on the properties of nanowires was investigated using scanning and transmission electron microscopy, energy dispersive x-ray spectroscopy, and x-ray diffraction. The growth process was based on the vapour–liquid–solid mechanism and the contribution of the diffusion-induced effect in this mechanism was confirmed by correlating the length and the diameter of the produced nanowires. The nanowires had diameters ranging from 30 to 70 nm and lengths between 1 and 2 µm. The growth axis of the nanowires was and the nanowires grew along directions of the substrate, independent of the substrate orientation used. The nanowires had stacking faults at the bottom and those grown at optimal conditions possessed perfect cubic structure near the top.