The harmonic response of tapered composite beams is investigated by using a finite element model. Only uniaxial bending is considered. The Poisson effect is incorporated in the formulation of the beam constitutive equations. Interlaminar stresses are evaluated by using stress equilibrium equations. The effects of in-plane inertia and rotary inertia are also considered in the formulation of the mass matrix. A parametric study is carried out to investigate the influence of taper profile and taper parameter. Linearly varying thickness variations of increasing, decreasing, decreasing-increasing and increasing-decreasing types are considered. © 1997 Academic Press Limited.