Aim: The aim of this study was to examine long-term implant success and marginal bone loss (MBL) of dental implants in postmenopausal women with osteoporosis/osteopenia. Materials and Methods: Postmenopausal women who underwent dental implant treatment at least 3 years ago were divided into two study groups [Test (osteoporosis/osteopenia) Group and Control Group] according to bone mineral density (BMD) measurements. Besides clinical periodontal and radiographic examinations, any implant failures were also recorded. Results: A total of 52 patients with a mean age of 59.51 +/- 5.66 years (Test Group; 26 patients, mean age: 60.61; Control Group; 26 patients, mean age: 58.42) were included in the study. Implant survival rates were 96.2% and 100% with a mean follow-up 60.84 +/- 22.13 and 60.07 +/- 20.93 months in Test and Control Groups, respectively (P > 0.05). While peri-implant PI (plaque index) and PD (probing depth) were not different between the groups, BoP (bleeding on probing) was significantly higher in Test Group (P = 0,026). Although MBL in Test Group was higher than Control Group (0.82 +/- 0,63 mm and 0.44 +/- 0,33 mm respectively), the difference was not found statistically significant (P = 0.069). Conclusion: Within the limits of this retrospective study, it can be concluded that postmenopausal osteoporosis/osteopenia does not affect MBL and long-term implant success. The findings suggest that dental implant therapy is a reliable treatment modality in these patients to improve the quality of life by increasing function and aesthetics.