The latest works are reviewed on analytical and applied pyrolysis of polymers, copolymers and blends. Improved identification, component analysis and structural elucidation were performed on several new polymers and copolymers. Various additives, catalysts and residual oligomers were analysed in plastics and the emission of toxic compounds under pyrolysis and combustion were monitored. The development of analytical pyrolysis methods (pyrolysis on line coupled to gas chromatography, mass spectrometry and/or infrared spectroscopy) is closely related to the advances in instrumental chemical analysis and to their combination possibilities. Publications on applied pyrolysis are concerned with the conversion of polymeric precursors into high performance materials (e.g. carbon fibers and ceramics) and the production of useful chemicals (e.g. monomers or fuels) from polymer wastes. In both analytical and applied pyrolysis, knowledge about the chemical reactions taking place is essential. Recent studies on the thermal decomposition mechanism of polyolefins, polystyrenes, acryl polymers, polyesters, polyethers, formaldehyde resins, polyamides, sulfur- and silicon-containing polymers are critically reviewed.