Composite sandwich structures have extensive applications due to their high strength and structural efficiency. Skew fibre-reinforced composite laminates are used as important structural elements in modern structural design, particularly in the aerospace industry. Natural frequency of these skew laminates is of primary significance to structural designers. The present article studies the free vibration and damping characteristics of sandwich skew plates consisting of composite stiff layers with viscoelastic (VEL) or electrorheological fluid (ER) core, using finite element method. The vibration behavior of these core materials is critically compared. Detailed analysis was conducted by varying the boundary conditions, core to stiff layer thickness ratios and stacking sequence. The inherent composite damping and the damping due to VEL (or ER fluid) core are investigated. The influence of electric field on the frequency and loss factor were also examined. © 2006 Elsevier Ltd. All rights reserved.