To compare the evidence of adjunctive antimicrobial photodynamic therapy in patients suffering from periodontitis and peri-implantitis. After a comprehensive literature search, studies were identified for treatment of aggressive and chronic periodontitis and peri-implantitis. The number of identified RCT's, comparisons, outcomes and length of follow-up were assessed. Meta-analyses are showen in forest-plots for probing depth reduction. There are great differences in the clinical evidence available concerning adjunctive aPDT in the treatment of periodontitis and peri-implantitis. Keywords: antimicrobial photodynamic therapy, periodontitis, peri-implantitis, meta-analyses