An analysis is presented for the free vibration characteristics of isotropic and laminated composite truncated circular conical shells including transverse shear deformation. All components of translatory and rotatory inertia are included. The applicability of linear shell theory due to Reissner is assumed, and governing equations are solved for the natural frequencies and mode shapes by using a combination of modal iteration and transfer matrix approach for different boundary conditions. Natural frequencies are compared with those predicted by the classical shell theory only for the lowest meridional mode of vibration corresponding to various circumferential wave numbers. Results indicate that the natural frequencies found by the improved shell theory equations may differ more than 50%, even for the lowest meridional mode, from the frequencies found by the classical shell theory equations depending on the boundary conditions, length, thickness, circumferential wave number, and lamination arrangement. © 1990 American Institute of Aeronautics and Astronautics, Inc., All rights reserved.