Plastics play an important role in our lives due to their versatility, lightness and low production cost. They can be found in almost every industry such as automotive, construction, packaging, medical, and engineering applications among others. Polyethylene terephthalate is one of the most consumed plastics worldwide in the packaging sector, which is why its useful life is usually very short, causing serious problems due to high disposal in the environment and urban landfills. The thermochemical degradation of PET has been studied by some researchers and it has been found that its degradation products are of high added value, which is why this work focuses on presenting the results obtained in the literature.