Abdel-Aziz Abdel-Hafez Abdel-Nabi^a, Ahmed KhalifaKhalifa^b, NesreenElmekawy ^{C aGraduate student, Department of Removable Prosthodontic, Faculty of Dentistry, Mansoura University, Dentist in the Ministery of Health,  Mansoura, Egypt. bLecturer of Removable Prosthodontic, Department of Removable Prosthodontic, Faculty of Dentistry, Mansoura University, Mansoura, Egypt. cProfessor of Removable Prosthodontic, Department of Removable Prosthodontic, Faculty of Dentistry, Mansoura University, Mansoura, Egypt.}   Abstract: Objective: to evaluate peri-implant outcomes of mandibular implant overdentures with Equator attachment and Locator attachment at criterion inter-implant distance. Material and methods: twelve completely edentulous patients have participated in this study. For each patient two implant were installed in the canine area of the mandible with 19 mm inter-implant distance according to the standardized two-stage surgical technique. Equator and locator attachment were loaded after two months of the surgery. Clinical evaluation were performed immediately, six months and twelve months following the final prosthesis insertion. Results: Clinical results revealed no significant differences in modified plaque index , modified gingival index, modified bleeding index and peri-implant probing depth in both groups at different follow up periods. Conclusion:implant assisted overdenture with equator and locator attachment may be a successful options. Keywords: implant assisted overdenture, OT Equator, Locator.