We have developed a Bi2O3 electrolyte doped with Dy2O3 and WO3 (DyWSB) that exhibits a higher conductivity than that of 20 mol% erbia stabilized bismuth oxide (20ESB), thus, giving it the highest conductivity of any known solid oxide electrolyte. Electrical conductivity results of the Dy-W stabilized bismuth oxide system are presented. The dopants were selected based on their polarizability and its effect on structural stability and conductivity. At 800 degreesC, the conductivity of (BiO1.5)(0.88)(DyO1.5)(0.08)(WO3)(0.04) is 0.57 S/cm (1.5 times as high as that of 20ESB), and at 500 degreesC, the conductivity is 0.043 S/cm (2 times as high as that of 20ESB).