This Account deals with the synthesis and characterization of monodisperse soluble oligothienylenevinylenes with chain lengths up to 100 Angstrom. The chain length dependence of the electronic and electrochemical properties both in solution and in the solid state are analyzed and discussed in the context of the potential use of oligothienylenevinylenes as molecular wires. Problems related to interchain interactions are illustrated by the analysis of the effects of structure on the reversible dimerization of cation radicals and by the synthesis of new series of end-substituted oligomers.