This work presents the results of a validation study using the forest growth simulation model MOSES 3.0 for Swiss forest conditions. During the latest parameterization of the model a large data set from Austria as well as Switzerland was used. The goal of this work was to validate the diameter and height increment functions using a large and independent data set (not used for model calibration) recorded on permanent sample plots in Switzerland. Tree growth was simulated over several growth periods and analyzed for a possible bias. The main results of this study suggest that no systematic discrepancies exist between the predicted and the observed diameter and height increment.