Purpose: this prospective study was done to evaluate the clinical and radiographic outcomes of mandibular implant supported over denture using two regular implants and two mini-implants. Methods: Sixteen patients were selected for the study and divided to Group I (control) who receiveda two conventionalimplants and group II (test) that receiveda two mini implants. Retention force of dentures, Bite force and Masticatory efficiency tests were. Evaluation for ridge loss was done using CBCT. The results were statistically analyzed by one-way ANOVA test. Results: the control group hada statistically significant incrementof the clinical features and a statistically significant decrement of ridge resorption than the test group. Conclusions: Mandibular implant supported overdenture by two mini implant has lower retention, biting force, and masticatory efficacy than the overdenture supported by two conventional implants. Also, it is associated with more radiographic ridge loss than overdenture supported by two conventional implants.