The transfer matrix method is used for the numerical solution of both in-plane and out-of-plane free vibration problems of symmetric cross-ply laminated composite beams. The rotary inertia, and both shear and extensional deformation effects, are considered in the analysis. A distributed parameter model is used in the mathematical formulation of the free vibration problem. The overall transfer matrix of the beam is obtained making use of the series solution of a set of differential equations. All the effects of the boundary conditions, the slenderness ratio, the ratio of the height to the width of the rectangular cross-section, the number of plies, and material types on the free vibration frequencies are studied. Comparison of the exact natural frequencies obtained in this study with the existing results is quite good. Copyright (C) 1999 John Wiley & Sons, Ltd.