Organic-inorganic hybrid single crystals of [2,3-(CH3)2C6H3NH3]4BiBr6NO3.2H2O were obtained by slow evaporation at room temperature and characterized by X-ray diffraction, IR and solid state NMR. This compound crystallizes in orthorhombic non-centrosymmetric space group Pca21 with the following lattice parameters: a = 25.8217(1), b = 7.8909(2), c = 21.4328(3) Å, V = 4367.07(13) Å3 and Z = 4. The structure was refined to R = 0.057 for 7069 independent reflections. The crystal is built up of 2,3-dimethylanilinium cations, [BiBr6]3−, disordered [NO3] anions and water molecules. The crystal packing is governed by a three-dimensional network of O-H…O, N-H…O and N-H…Br hydrogen bonds and van der Waals interaction. The infrared spectrum has been interpreted on the basis of literature data. Solid state 13C CP-MAS-NMR spectrum is in agreement with the X-ray structure.