Bi(1-x)A(x)MnO(3) (A = Sr, Ca; 0.40 <= x <= 0.55) systems have been synthesized by solid state reaction method to investigate the effect of two different cations substitution in place of Bi3+. All samples are monophasic as observed in X-ray diffraction. The Bi1-xSrxMnO3 shows the tetragonal symmetry whereas, Bi1-xCaxMnO3 shows orthorhombic as confirmed by Rietveld refinement. The Bi1-xSrxMnO3 system shows higher conductivity as compared to Bi1-xCaxMnO3. Bi0.50Sr0.50MnO3 exhibits highest conductivity of 180 S/cm at 790 degrees C which can be attributed to its higher specific free volume and uniform grain size with better distribution in entire structure. Sr2+ doped system has lower thermal expansion coefficient as compared to Ca2+ doped system. (C) 2014 Elsevier B.V. All rights reserved.