Sandwich beam having viscoelastic core is analyzed for its buckling and vibration behavior under thermal environments, using the finite element method. Variation of natural frequencies and loss factors with respect to temperature is investigated. The formulation is based on the displacement field proposed by Khatua and Cheung [International Journal for Numerical Methods in Engineering 6 (1973) 11-24]. The behavior of the beam considering both the temperature dependent and independent shear modulus of the core is studied. A parametric study is conducted with core thickness as parameter and its influence on buckling temperatures, natural frequencies and loss factors is studied. Two different core materials are considered for the analysis to find the influence of material on buckling and vibration behaviors. © 2005 Elsevier Ltd. All rights reserved.