Silica "nanorattles" are fabricated by means of selective etching of ingeniously designed organic-inorganic hybrid silica spheres with a three-layer "sandwich" structure. The size (95-645 nm), shell thickness, and core diameter of the monodisperse nanorattles can be precisely controlled, even in gram-scale production. This method is also shown to be promising for development as a general method for synthesis of rattle-type functional nanomaterials.