Electroluminescent polymers are reviewed in terms of synthesis and relationships between structure and light emission properties. The main concepts, problems and ideas related to the subject as a whole and to each class of electroluminescence (EL) polymer, have been systematically addressed. The elements of device architecture were considered, such as electrode characteristics and transport layers. The main mechanisms for light emission were approached, and the relevant issues related to color tuning were discussed in general terms and taking into account the structural features of each polymer structure, as well. The main routes for the synthesis of each EL polymer class are described, illustrated with numerous examples, including PPV and PPV related structures, polythiophenes, cyanopolymers, polyphenylenes, silicon-containing polymers, conjugated nitrogen-containing polymers, polyfluorenes, polyacetylenes and polymers with triple bonds in the main chain, condensation polymers.