Purpose: To compare the qualitative and quantitative profile of Epstein-Barr virus (EBV) at external and internal implant surfaces between participants with peri-implantitis and healthy peri-implant tissues and to quantitatively assess the relation between EBV and periopathogens inside the microbiologic profile associated with peri-implantitis. Materials and Methods: Microbiologic specimens were retrieved from 84 patients wearing 190 implants to estimate the levels of EBV and 10 periopathogens in the peri-implant pocket and internal-implant connection using quantitative polymerase chain reaction. Results: The study sample consisted of 113 healthy and 77 peri-implantitis-affected implants. Statistical significance was not reached in EBV prevalence between peri-implantitis and healthy controls. EBV-positive participants demonstrated higher levels of Prevotella intermedia (Pi) and Campylobacter rectus (Cr) compared with EBV-negative participants. A positive correlation was demonstrated among EBV and Tannerella forsythia (Tf), Parvimonas micra (Pm), Fusobacterium nucleatum (Fn), and Cr levels in peri-implantitis-affected implants, while healthy controls demonstrated a positive correlation between EBV and Aggregatibacter actinomycetemcomitans (Aa), Pi, and Pm. Conclusion: EBV cannot be considered as a microbiologic marker of peri-implantitis. However, EBV could be considered as a risk factor and a peri-implantitis enhancer based on its positive correlations with pathogens associated with peri-implantitis. Schlagwörter: Campylobacter rectus, Epstein-Barr virus infections, Fusobacterium nucleatum, peri-implantitis, Prevotella intermedia