In this research, the static and dynamic behavior of plates, with a general isotropic viscoelastic constitutive relation, is examined The viscoelastic constitutive equations are written in the Boltzmann-Volterra form. It is well-known that in this form the operator has two different kernels, which make the solution somewhat difficult. In this research, constitutive equations existing in literature are expressed in operator form. The solution technique systematizes the solution of the viscoelastic problem and gives better results in comparison with existing methods in literature. The developed solution technique is applied to triangular plates under static and dynamic loads. (C) 2000 Elsevier Science Ltd. All rights reserved.