The development of our forests under climate change and the influence of today’s actions on future ecosystem services in forests have become important silvicultural issues. There-fore, model-based tools are needed for forest planning and the optimization of interventions. In this article the new, scientifically based forest growth model SwissStandSim is presented, which shall become part of a future decision support system for the Swiss forestry. SwissStandSim is based on the data of the long-term experimental growth and yield plots in Switzerland. These data are used to create a climate sensitive single-tree based forest growth model. The tree data were combined with many environmental variables to model the demographic processes of management, growth, mortality and ingrowth. The climate variables showed ecologically in-teresting interactions, especially between precipitation and temperature, both for growth and mortality. A further inter-action was found between the intensity of forest management and mortality. The stronger the management, the higher the mortality in the following years. This allows inter-pretations regarding the vulnerability of stands after major interventions. Simulations with SwissStandSim for three exemplary growth and yield plots show a good agreement between data and model, with the frequency and intensity of natural disturbances playing a key role. The calibration of SwissStandSim was based on a mean disturbance regime, which can lead to an over-or underestimation of mortality depending on the local situation. With SwissStandSim the management of forest stands can be simulated flexibly. Thus, SwissStandSim is very suitable to become part of a practical tool for decision support in silvicultural questions at the stand level developed in the WSL project SessFor (NFP73).