Objective: The purpose of this study was to evaluate periimplantitis prevalence in patients using implant-supported fixed prostheses that did not have any routine maintenance care. Method and Materials: A total of 161 implants (27 patients) were evaluated in patients using implant-supported fixed prostheses. Collected data included information related to patient general health and local factors such as characteristics of implants, time in function, type of loading, positioning, Modified Bleeding Index, bacterial plaque, bleeding on probing (BOP), marginal recession, probing depth (PD), keratinized mucosa, and radiographic bone loss (BL). Factors related to the prostheses were also evaluated. The exclusion criteria were patients that have had any follow-up visit for plaque control of the prosthesis and/or the implants. Results: From a total of 161 implants, 116 (72%) presented without peri-implantitis (PD > 4 mm + BOP + BL > 2 mm) while 45 (28%) had some sign of the disease. Implants placed in the maxilla were 2.98 times more likely to develop the disease (P .05). Moreover, patients aged ≤ 60 years old were 3.24 times more likely to develop peri-implantitis (P .05). Another analysis with statistical relevance (P .05) was that implants with less than 3 mm interimplant distance were three times more likely to have peri-implantitis. There was no statistical relevance considering other analyses. Conclusion: It can be concluded that patients aged ≤ 60 years have a greater chance of presenting periimplantitis, as well as for implants positioned in the maxilla and those placed with an interimplant distance 3 mm. Schlagwörter: fixed prostheses, local factors, marginal bone loss, peri-implantitis, prevalence