The effect of a two-layer soil system on the behavior of a laterally loaded pile is investigated analytically in nondimensional terms. A modulus of subgrade reaction is used to define the soil stiffness; the stiffness of the surface layer is defined in terms of that of the underlying layer. The complete range of relative stiffness and relative thickness of the two layers is investigated. The surface layer is shown to exert an overwhelming influence on the behavior of a soil-pile system.