Stresses in the filler material of three-layer cylindrical shell with orthotropic loadbearing layer of structural fiberglass and lightweight filler type polyurethane foam were investigated. The effect of elasticity of the filler material on the stresses in the bearing layers of three-layered shells of rotation under the action of the ring load is shown. The given results enable to estimate the error of the widespread assumptions regarding the cross noncompressibility of the filler in the calculation of three-layered shells.