Recently, Dynamic Voltage Restorer (DVR) has become a popular power electronic device as a protection for sensitive loads from voltage sag. Voltage sag widely known as one of the major problem in power quality, it is defined as a short reduction of voltage from the nominal. DVR is a custom power device for voltage sag mitigation which works when the fault occurs in power distribution system. In this paper, the effect of the DVR location is investigated at the low and medium voltage of the distribution system with different loads. To verify the performance of the DVR in mitigating the voltage sag, the system is simulated using PSCAD/EMTDC software. Results show the effect of DVR location in maintaining the voltage sag.