Abstract: Background – Peri-implant diseases need early diagnosis and intervention in order to prevent implant failure. Periostin is an enzyme imperative for periodontal health which decreases with increasing severity of inflammation and levels revert back to normal after treatment. Alterations in the levels of periostin with relation to peri-implant diseases is not yet been investigated. This study aims to explore the role of periostin in peri-implant health and disease. Objectives: To evaluate and compare the levels of Periostin in peri implant sulcular fluid (PISF) in healthy peri-implant sites and sites with peri-implant mucositis and periimplantitis with its clinical correlation. Method and design: Total of 66 implant sites loaded at least one year earlier will be included in this study and divided into three groups. Group I (healthy peri-implant tissues), group II (peri-implant mucositis), and group III (periimplantitis). Levels of periostin in peri-implant sulcus fluid (PISF) acquired by microcapillary pipettes acquired by micro-capillary pipettes will be determined from each group using human periostin ELISA kit. Results: The results will be analyzed as levels of periostin in peri-implant sulcular fluid recorded by ELISA in all the three groups and will be subjected to intergroup comparison and will be presented after statistical analysis. Conclusion: Levels of periostin in peri-implant sulcular fluid may prove to be a magnificent tool in early and prompt diagnosis of peri-implant diseases which will help in planning and execution of appropriate treatment, hence preventing further destruction of supporting tissues increasing longevity of dental implants.