The first-principle quantum-chemical calculations of elastic constants for beryllium oxide and their approximation (the Voigt-Reuss-Hill model) for a polycrystalline material are used to derive quantitative estimates of several thermomechanical parameters of BeO ceramics: isothermal compression coefficient, sound velocity, the Debye temperature, and coefficients of linear and volume temperature expansion, as well as the temperature dependence of molar heat capacity and thermal conductivity. The results are discussed in correlation to available experimental data. © Springer Science+Business Media, Inc. 2006.