Background The main objective of the present systematic review is to know the mechanical and functional properties of PEEK (polyetheretheretherketone) abutment and to find out if it is a potential substitute for titanium abutments. Material and Methods An electronic search was conducted in 5 databases: Medline (Pubmed), SciELO, Cochrane, Web of Science (WOS) and Google Scholar. Studies published from 2018 to 2020 and written in English were included. The protocol of this systematic review was registered in PROSPERO (ID 274834). Subsequently, data extraction and quality analysis were performed according to the modified CONSORT guidelines. Results Initially, a total of 976 articles were obtained. Using Mendeley Desktop, duplicates were discarded, reducing the number of articles to 483. After reading abstracts, 448 articles were excluded. Finally, 35 full-text articles were analysed, of which 5 articles were included in this systematic review. Conclusions The available evidence shows that PEEK implant abutments do not have sufficient biomechanical requirements to replace the definitive titanium abutment. However, it is considered as an alternative and provisional material, especially if placed in the anterior region. Key words: Abutment, polyetheretheretherketone, titanium, dynamic fatigue, fracture toughness, loss of torque.