In this paper, we propose a new dynamic power management (DPM) system based on fuzzy decision support system. Different dynamic power management policies may be implemented in the system. Based on the system requirements for each application class, one of the policies may be selected automatically. The approach, which is not dependent on the system under management, can be utilized in different systems. To show the efficacy of the fuzzy decision support system, we have compared its performance with fixed DPM policy systems. The results show that considerable improvements may be achieved in this approach compared to those systems with one DPM policy.