An aerofoil 26 for a gas turbine engine (10, Fig. 1) comprises a cavity 38, a cellular material 42 located in the cavity 38 for stiffening the aerofoil 26, and a vibration damping medium 44 located in the cavity 38 for damping the aerofoil. The cellular material 42 is preferably a metal foam bonded to the inner surface 34a, 36a of the hollow aerofoil 26, and the vibration damping medium 44 is preferably a viscoelastic material. Various methods for fabricating the aerofoil 26 are also described.