Single cyrstalline ZnTe layers have been successfully grown on (001) GaAs substrates by hot wall epitaxy at substrate temperatures between 280-370-degrees-C. The vapor phase near the substrate surface was investigated by a quadrupole mass spectrometer. Transmission electron microscopy, reflectivity, and photoluminescence were used for growth optimization, impurity identification, and strain determination. The biaxial inplane strain is about epsilon parallel-to = -0.5% at the interface and epsilon parallel-to (320-degrees-C) = -0.06% at the surface for thicknesses of 1-5 mum. Two luminescence peaks can be assigned to As and N.