Various pi-conjugated polymers are accessible via organometallic polycondensation reactions mediated by organic transition-metal complexes. For example, Ni(0)-promoted dehalogenation polycondensation reactions of dihaloaromatic compounds, X-Ar-X, afford polyarylenes, -(AR)(n)-. Pd-catalyzed polycondensations give poly(arylene ethynylene)s, -(Ar-C=C-Ar'-C=C)-(n). These polymers are electrochemically active, electrically conductive, and light-emitting. Their well-characterized linear structure brings about a unique packing of the polymer molecules in the solid. In this review, the preparation of pi-conjugated polymers by means of organometallic polycondensation, their basic properties, ordered structure in the solid state, and applications in electronic and optical devices are summarized.