The main causes of residual stresses in thin alloy layers before and after annealing are the thermal mismatch between the substrate and the layer, misfitting precipitates, dislocations, impurity atoms and vacancies. Models to predict the macro- and microstresses in thin layers containing misfitting precipitates and vacancies are discussed. Examples are given for basically different alloy layer systems, prepared by magnetron sputtering, to validate the models: Mo-Ti layers that exhibit only stresses caused by misfitting precipitates, and Ag-Ni layers where only thermal stresses occur.