CsSrI3:Eu2+ was previously reported by our group as a highly efficient scintillator, and we now report the advantages of partial replacement of Sr by Ba. Scintillation and physical properties of CsSr(1-x)BaxI(3):Eu2+ crystals are presented for 0 <= x <= 0.24, We found that the hygroscopicity decreased with increasing Ba concentration while density and effective atomic number increased, thus enhancing the X-ray and gamma ray detection efficiency. The scintillation light yield ranged from 22,000 to 28,000 photons per MeV for Ba concentrations between 3% and 24%. The principle scintillation decay time ranged from 1.8 to 2.1 mu S. (C) 2013 Elsevier B.V. All rights reserved,