The incorporation of distributed generation (DG) under the virtual power plant (VPP) paradigm allows the coherent central control, and the coordinated market integration of several and widely dispersed electric power sources. That way, VPPs can participate in frequency control by regulating in a coordinated manner their output power for the sake of system stability. This study analyzes a decision tree (DT)-based methodology that dispatches a requested reduction of active power within a VPP (among the sources it consists of), so as to support the mitigation of over-frequency. The presented control con-cept finds its application concerning grid support in case of over-frequency, and is also meant as a response to related reports and studies asking for the increased contribution of DG to overcome such phenomena.