A comparative study is presented on the vibratory characteristics of isotropic and orthotropic cylindrical shells with perfectly bonded piezoelectric material on the inner and outer surface of the shell lamina. The variation of free vibration natural frequencies and active damping ratios are simulated under varying magnitude of steady state axisymmetric temperatures. The objectives are explained by presenting the results of the numerical study on cylindrical shells made of mild steel and HS-graphite/epoxy bonded with PZT piezoelectric material. The vibratory characteristics under the above circumstances are interpreted from the point of view of initial stresses developed due to thermal loading. Apart from this, the changes in the vibratory characteristics due to different fiber orientations are examined. It is found from the studies that the frequency characteristic with respect to fiber orientation under thermal environment is highly dependent on the boundary condition considered for the shell laminate. © 2003 Elsevier Ltd. All rights reserved.