A straightforward synthesis of α,β-unsubstituted and α-halogenated naphtho[2,3-b:6,7-b']dithiophenediimides (NDTIs) is described. Electrochemical and optical studies of N,N-dioctyl-NDTI demonstrate that the compound has a low-lying LUMO energy level (4.0 eV below the vacuum level) and a small HOMO-LUMO gap (~2.1 eV). With its interesting electronic and optical properties, in addition to its planar structure, NDTI is a promising building block for the development of novel π-functional materials. In fact, it afforded n-channel, p-channel, and ambipolar materials, depending on the molecular modification.