Objective: To evaluate the outcome of combined therapy of peri-implantitis in patients with type 2 diabetes mellitus. Methods: Study included 46 patients with type 2 diabetes mellitus diagnosed peri-implantis. 24 implants with early peri-implantitis, 18 implants with moderate peri-implantitis. The diagnostic parameters used for assessing peri-implantitis include clinical indices, Probing Pocket Depth (PPD), Bleeding on Probing (BOP), peri-implant radiography, data at the re-examination were retrospectively compared to baseline data. Patients underwent treatment with HbA1c levels <7.2% or less than 154 mg/Dl. Results: A statistical significant reduction in both PPD and BOP were seen at all-time points as compared with the baseline clinical measurements. Stable clinical measurements PPD and BOP were demonstrated after 1 year the initial treatment, remaining stable during the following three years. The mean BOP in patients before treatment of peri-implantitis was 2.5 ± 0.31, after 6 months treatment month treatment 0.6 ± 0.1. The mean PPD in patients before treatment of peri- implantitis was 5.2 ± 0.24, after 6-month treatment pocket was 3.2 ± 0.1. Conclusion: Conservative treatment with systemic antibiotics, pocket elimination was an effective therapy in peri-implant mucositis and еarly periimplantitis, when peri-implantitis category moderate surgical treatment combined conservative therapy effective method in patients with type 2 diabetes mellitus.