This work deals with vibration behavior of sandwich beams made of fiber-glass laminate skins wrapped over polyurethane foam core. Experimental and numerical investigations on the natural frequencies of both flat and curved beams with and without debond were carried out. The vibration tests were performed for clamped-clamped end conditions using an impulse-frequency response method. Finite element analysis was carried out using ABAQUS. Results indicate that fundamental natural frequencies are seriously affected by curvature angle and debond, whereas the higher order natural frequencies show relatively small changes. Face/core debond causes reduction of the natural frequencies.