The optical Stark spectrum of the A(1)Sigma-X-1 Sigma(+)(0, 0) band of BaO was recorded and analyzed to determine the permanent electric dipole moments, mu, for the A(1)Sigma(nu = 0) and X-1 Sigma(+)(nu = 0) states to be 3.125(16) D and 7.869(17) D, respectively. The molecular beam electric resonance data for the X-1 Sigma(+)(nu = 0) states [L. Wharton, M. Kaufman, W. Klemperer, J. Chem. Phys. 37 (1962) 621] was re-analyzed to produce mu of 7.9530(4) D. The systematic difference between the MBER and optical Stark values is discussed. (C) 2009 Elsevier B.V. All rights reserved.