To develop a model for the growth of epitaxial phase change materials, it is very important to investigate the different kinetic adatom processes such as adsorption, desorption, and surface diffusion. Especially desorption is a key parameter which may significantly influence growth rate, material quality and composition, as well as surface morphology. Here, we present a detailed desorption study during deposition of GeTe thin films on Si (111) substrates taking into account the nucleation regime.