On the basis of the new flexural theory of elastic sandwich plates recently developed [1–3], the problem of general forced flexural vibration of sandwich plates in the plane-strain case is solved. The classical method of separation of variables combined with the Mindlin-Goodman procedure [4] for treating time-dependent boundary conditions is used. As an example, the results are made use of in solving the problem of a simply supported sandwich plate in plane strain with one of the two end sections prescribed a transverse deflection varying with time.