Abstract Background. Peri-implantitis is a chronic disease that can lead to implant loss. The literature data describe that none of the methods studied completely solve the problem. Several surgical treatments have been proposed to treat peri-implantitis, but their results does not allow for an ideal approach to be established. Objective of the study. This study aims to compare two regenerative surgical treatments for peri-implantitis. Material and Methods: Ten patients with peri-implantitis were included in the study. The control group (CG) received regenerative treatment with a xenogen bone substitute and a resorbable membrane, while the test group (TG) received the same bone substitute along with a PRF membrane. The following outcome variables were assessed: peri-implant probing depth (PiPD), modified bleeding index (mBI), modified plaque index (mPI), suppuration (SUP) and radiographic bone changes. Results. Peri-implantitis was defined as radiographic bone loss ≥3mm and/or probing depths ≥6mm, accompanied by profuse bleeding. All subjects had previously undergone non-surgical treatment. All study participants were closely monitored through a maintenance program. At the 6-month follow-up, both groups showed clinical and radiographic improvements. No implants losses due to the progression of peri-implantitis. The reduction in clinical indices, mPI and PiPD, were similar between the study and control groups (p>0.05). However, the GC group demonstrated a statistically significant greater reduction in the clinical index mBI (p=0.02). There was no statistically significant difference in radiographic bone changes between the two groups (p>0.05). Conclusions. Regenerative treatment, when appropriately indicated, yields successful results in peri-implantitis. Both methods resulted in stable conditions. However, the use of a resorbable membrane did not improve outcomes compared to the PRF membrane. Keywords: peri-implantitis, PRF membrane, regenerative surgical treatment.