In the present study, the stability of gaseous barium silicates was confirmed by the high temperature mass spectrometry. On the basis of equilibrium constants measured for gas-phase reactions, the standard formation enthalpies were determined for gaseous barium silicates as (-510 +/- 15) kJ (.) mol(-1) and (-884 +/- 18) kJ (.) mol(-1) at 298 K; standard atornization enthalpies as (1637 +/- 17) kJ (.) mol(-1) and (2318 +/- 20) kJ (.) mol(-1) at 298 K for BaSiO2 and BaSiO3, respectively. Based on the results obtained the critical analysis of the literature data was carried out. (c) 2006 Elsevier Ltd. All rights reserved.