A series of oligoselenophenes with well-defined structures up to the hexamer has been synthesized using the Stille coupling reactions, and their physical properties have been studied by electronic absorption and emission spectroscopy as well as cyclic voltammetry. Their spectra systematically change with increasing conjugated chain lengths, and the correlations are reminiscent of those for oligothiophene series, suggesting that conjugation forms of both pi-electronic systems are very similar. In addition, the oligoselenophenes, on iodine doping, have relatively high conductivities comparable to those of the oligothiophene counterparts, which increase lip to approximately 10(-2) Scm(-1) with an increasing number of the selenophene units.