A new stannosilicate Cs2SnSi3O9 has been synthesized and characterized by single-crystal X-ray diffraction and solid-state NMR spectroscopy. It crystallizes in the orthorhombic space group P2(1)2(1)2(1) (No. 19) with a = 7.9612(7) angstrom, b = 10.3444(9)