Purpose: This study evaluated the retrospective outcomes of implant-borne dental rehabilitation in patients with mandibular defects reconstructed with a fibula free flap. Materials and Methods: Patients with segmental mandibular defects were enrolled in this cohort study. Defects in these patients were caused by oral neoplasm, trauma, and osteoradionecrosis. The patients were treated with a fibula free flap procedure and dental implant-borne prostheses between 1988 and 2010. Clinical and radiographic data were evaluated; Kaplan- Meier survival analysis and Poisson regression analysis were used to evaluate implant survival parameters. The statistical significance (α = .05) of the results was determined. Results: Seventy-four patients were selected in this study. All patients were available for continuous follow-up. Nine patients (12.1%) developed fibular graft complications postoperatively: 3 in donor sites and 6 in recipient sites. One hundred ninety-two implants were inserted, and 18 implants failed (9.3%). Overall implant survival in patients was 90.1%, 83.1%, and 69.3% after 5, 10, and 20 years, respectively. In 152 implants, probing depth (PD) ranged from 2 to 3 mm. In 31 implants, PD was greater than 5 mm. In 9 implants, PD was greater than 7 mm. The highest implant failure rates were expected for men (odds ratio [OR] = 2.948; 95% confidence interval [CI], 1.10 to 7.85; P = .031), patients receiving primary fibula free flap reconstruction (OR = 3.696; 95% CI, 1.16 to 11.73; P = .027), and patients receiving radiotherapy (OR = 5.269; 95% CI, 1.40 to 19.7; P = .014). Conclusion: Fibula free flap procedures and implant-borne prostheses proved to be reliable approaches for rehabilitation of mandibular defects and oral function. The overall postoperative fibula free flap and peri-implant complication rates proved to be low. Regular follow-up visits and proper oral hygiene maintenance contributed to the long-term successful treatments. Keywords: dental implant, fibula free flap, follow-up studies