A new layered indium selenide, [C7H10N][In3Se5] (1), has been prepared solvothermally using 3,5-dimethylpyridine as a solvent and structure-directing agent. This material, which was characterized by single-crystal and powder X-ray diffraction, thermogravimetric analysis, UV-vis diffuse-reflectance spectroscopy, IR. spectroscopy, and elemental analysis, crystallizes in the monoclinic space group P2(1)/c [a = 3.9990(4) angstrom, b = 16.7858(15) angstrom, c = 23.930(2) angstrom, and beta = 94.728(4)degrees], The crystal structure of 1 contains anionic layers of stoichiometry [In3Se5] - in which indium atoms with octahedral and tetrahedral coordination coexist. The [In3Se5](-) layers are interspaced by monoprotonated 3,5-dimethylpyridinium cations. A closely related material, [C7H10N][In3Se5] (2), was obtained when using 2,6-dimethylpyridine instead of 3,5-dimethylpyridine.