To evaluate the antimicrobial effect of nanocoated orthodontic archwires. A systematic review was conducted using the available electronic data bases which analysed the microbial adhesion after nano coating of orthodontic archwires against uncoated archwires. Due to the paucity of in vivo studies, invitro studies also were considered. Downs and Black checklist was used for risk of bias assessment. Data extraction was performed from each study and the results were tabulated. 6 studies which fulfilled the inclusion criteria were selected. Risk of bias assessment showed a medium to high risk of bias for most of the studies. The antibacterial effect of various nano coatings on the archwires were analysed. Most studies included in the systematic review showed medium risk of bias. Due to the severe diversity of the methods used to assess the antimicrobial action, a metanalysis was not possible. For further understanding of nanoparticles, their use and their antimicrobial action, in vitro studies with a low risk of bias and RCTs are required before they can be adopted for routine clinical practice.