A novel vanadium(IV) phosphite, (VO)(4)(4,4'-bpy)(2)(HPO3)(4), was hydrothermally synthesized and characterized by single-crystal X-ray diffraction, This compound crystallizes in the monoclinic system with the space group C2/c and cell parameters a = 35.970(3) Angstrom, b = 15.9400(13) Angstrom, c = 10.7681(7) Angstrom, beta = 101.073(4)degrees, and Z = 8 with R-1 = 0.0482. The structure of the compound consists of trigonal bipyramidal [VO4N] and pseudopyramidal [HPO3] blocks, which are connected by corner-sharing, to form vanadium phosphite layers in the bc plane. These layers are further linked through 4,4'-bpy pillars, generating a 3D framework. Thermogravimetric analysis and magnetic susceptibility data for this compound are given.