Chemical recycling of polymer materials enables complete or partial depolymerization of the macromolecular structure to generate low molecular weight compounds - monomers, oligomers or gases. Chemical recycling of poly(ethylene-terephthalate) by glycolysis, methanolysis and hydrolysis (acid- and base-catalyzed as well as neutral) and chemical recycling of polyethylene and polypropylene by pyrolysis were analysed. Glycolysis of PET yields the monomer bis(2-hydroxyethyl) terephthalate (BHET) along with its oligomers, methanolysis of PET results in dimethyl terephthalate (DMT) and ethylene glycol (EG) as the main products, while hydrolysis of PET leads to terephthalic acid (TPA) and ethylene glycol (EG). Pyrolysis of polyethylene (low-density polyethylene and high-density polyethylene) and polypropylene causes scission of the macromolecules whereby different gaseous and liquid fractions are obtained, depending on the type of polymer used as raw material for recycling. The effect of various reaction parameters on the depolymerization degree of PET and degradation of LDPE, HDPE and PP in the mentioned chemical recycling processes has been studied. It can be seen that better results were achieved in more aggressive reaction conditions, such as higher temperature, increased quantity of catalyst and chemicals together with longer reaction time.