Purpose: There is a lack of studies reporting long-term prevalence of peri-implant diseases in patients rehabilitated with overdentures and not receiving maintenance, which is a common situation. The aim of this cross-sectional study was to evaluate the patient satisfaction and rate of biologic complications in patients rehabilitated at least 7 years before with mandibular/maxillary overdentures, who for personal or economic reasons decided not to participate in a structured supportive maintenance program. Materials and Methods: Each of the patients filled out a health and dental history and a visual analog scale (VAS)-based satisfaction questionnaire; additionally, the patients received a clinical examination and a panoramic radiograph. The prevalence of peri-implant diseases and the patient satisfaction were reported. Moreover, presumed risk indicators of peri-implant diseases and implant loss were tested through univariate analyses and multivariate, time-adjusted, logistic regressions. Results: A total of 52 patients who received 63 overdentures on 252 implants were included. The included patients showed a high degree of satisfaction (mean VAS = 6.3; SD: 2.1) and very low discomfort rates and would repeat the type of rehabilitation (mean VAS = 6.99; SD: 2.6). The prevalence of peri-implantitis was 30.8% at patient level and 19.4% at implant level, while 23.1% of patients experienced implant loss at any time. A clear tendency toward increased prevalence of biologic complications after the eighth year of loading was noted. In loading time-adjusted regression analyses, bone-level implants were associated with a higher prevalence of recession with no/minimal inflammation (OR = 3.37; 95% CI: 1.16 to 9.77; P = .025), while the maxillary arch was associated with both severe peri-implantitis (OR = 4.18; 95% CI: 1.03 to 16.97; P = .046) and implant loss (OR = 9.27; 95% CI: 3.41 to 25.14; P = .000). Conclusion: Despite high levels of satisfaction, patients rehabilitated with overdentures not participating in a structured supportive schedule show high rates of biologic complications. For this reason, they should be strongly motivated, at the time of prosthesis delivery, to participate in a structured maintenance program. Schlagwörter: long term, patient satisfaction, peri-implant diseases, peri-implantitis, peri-implant mucositis, risk factors, supportive