Polymer electrolytes in the ternary PEO-CdSO4-DBP and PEO-CdCl2-DBP systems have been synthesized using solution casting technique. The resulting polymer electrolyte films are translucent, bubble-free and mechanically flexible. The ternary polymers have been characterized using FTIR spectroscopy, optical microscopy, SEM and DSC techniques. The electrical conductivity of PEO-CdSO4-DBP and PEO-CdCl2-DBP systems at room temperature are at least 10 times higher compared to the corresponding nonplasticized binary systems. The room temperature conductivity changes by an order of 10(-9) S cm(-1) for nonplasticized PEO-CdSO4 to 1.45x10(-8) S cm(-1) with 48.22 wt.% DBP. For PEO-CdCl2 system, room temperature conductivity changes from an order of 10(-9)-2.06x10(-8) S cm(-1) with 42.58 wt% DBP. The conductivity is found to depend on the concentration of the DBP.