Aim: To examine the existing evidence in identifying risk indicators in the etiology of peri-implantitis. Material and methods: A literature search was performed in MEDLINE via PubMed database of the US National Library of Medicine, for articles published until October 2014 using Medical Subject Heading search terms + free text terms and in different combinations. Results: The microbiota associated with peri-implantitis is complex, demonstrating differences and similarities to the one seen at periodontitis sites. Plaque accumulation at dental implants triggers the inflammatory response leading to peri-implant mucositis/peri-implantitis. Individuals with a history of periodontal disease and smokers have an increased risk of developing peri-implantitis. There is some evidence to support the role of genetic polymorphism, diabetes, and excess cement as risk indicators for the development of peri-implantitis. There is also evidence to support that individuals on regular maintenance are less likely to develop peri-implantitis and that successful treatment of periodontitis prior to implant placement lowers the risk of peri-implantitis. Conclusions: Plaque accumulation at implants will result in the development of an inflammation at implants. A history of periodontal disease, smoking, excess cement, and lack of supportive therapy should be considered as risk indicators for the development of peri-implantitis. © 2015 John Wiley & Sons A/S.