Polymers containing carbazole units in the main chain – either as homopolymers or copolymers – have been prepared by a variety of methods of which transition-metal mediated crosscoupling reactions have been the most successful. The properties of these materials and thus their potential as active materials in a variety of optoelectronic devices depend crucially upon the way in which the carbazole units are linked – either 3,6-, 1,8-, 3,9-, and 2,7-carbazolylene units being known. Of these the 2,7-carbazolylene units are not accessible from carbazole, and are made in a short high-yielding total synthesis from a commercially available material, while the other units can be made in a few high yielding steps from the readily available carbazole. In addition, ladder-type polycarbazolylenes have been prepared in which the units are linked simultaneously through both the 2,7- and 3,6-positions. In this chapter we show how carbazole-based polymers of all the above types can be prepared efficiently and provide a brief summary of the effects of structural isomerism upon their properties and upon the synthetic methodology required in their preparation.