Proton conducting oxides Ba 1−x Sr x Ce 0.65 Zr 0.2 Y 0.15 O 3−ı (0 ≤ x ≤ 0.25) are prepared using the citrate-EDTA complexing sol-gel method. The effect of strontium and yttrium doping on the material properties is systematically investigated. The phase formation, thermal analysis, morphology, stability and conductivity measurements are performed on the sintered powders through TG-DTA, XRD, SEM, EDAX, FTIR, Raman and LCR measurements. The results indicated a single-phase orthorhombic system. Strontium incorporation helped in increasing the grain size up to 20% of strontium doping while reducing the lattice parameters and unit cell volume. The ionic conductivities of the Ba 1−x Sr x Ce 0.65 Zr 0.2 Y 0.15 O 3−ı sintered oxides increased with increase in the concentration of Sr 2+ along with the co-doping strategy of trivalent Y 3+ in the B site. Among the synthesized samples, Ba 0.8 Sr 0.2 Ce 0.65 Zr 0.2 Y 0.15 O 3−ı pellet with orthorhombic structure showed highest conductivity with a value of 2.35 × 10 −1 S/cm and 2.41 × 10 −1 S/cm at 500 • C due to its smaller lattice volume, larger grain size and lower activation energy that led to excessive increase in conductivity. All pellets exhibited good chemical stability when exposed to air and H 2 O atmospheres. These results indicate that this composition can be used as a potential electrolyte if synthesis conditions and temperature are well maintained.