It is reported that peri-implantitis does not heal favorably following nonsurgical therapy. In this case study, three consecutive peri-implantitis patients with concomitant history of periodontitis were treated with nonsurgical therapy and reassessed up to 12 months following treatment. All treated peri-implantitis sites showed a considerable reduction in probing pocket depth, attachment loss, and bleeding on probing. This was also associated with bone fill of the vertical bony defects around the previously exposed implant threads. This case report shows that a degree of clinical resolution and radiographic bone fill can occur without the use of adjunctive antibiotics in peri-implantitis lesions of patients with periodontitis. Schlagwörter: nonsurgical treatment, peri-implantitis, periodontitis, radiographic bone fill