A method for the fabrication of hollow silica nanospheres, a facile one-pot hydrothermal route, is described. Heating of an aqueous solution of water glass and D-glucose to 180 °C for 24 h affords-as indicated by transmission electron microscopy-a nanospherical composite consisting of a silica shell sheathing a carbonaceous core. Subsequent removal of the carbonaceous interior through oxidation in air produces hollow silica structures. Variation of the concentration of the two jointly dissolved chemicals enables a variation of the thickness of the silica shell. The hollow silica particles were characterized by means of SEM, TEM, XRD, IR spectroscopy, thermogravimetrical analysis (TGA), and sorption measurements.