Purpose: The purpose of this finite element analysis study was to evaluate the effect of single implant position (central, canine) and denture base materials (conventional acrylic resin, glass fiber reinforced acrylic resin) on stress distribution in single implant supported mandibular overdenture. Materials and methods: Two 3 dimensional finite element models of mandibular overdenture supported by a single implant were designed in solid works 2015 software; model I a single implant in central region with conventional acrylic resin denture base, model I b single implant in central region with glass fiber reinforced acrylic resin denture base, model II a single implant in canine region with conventional acrylic resin denture base, model II b single implant in canine region with glass fiber reinforced acrylic resin denture base. A 300 N vertical and A 300 N oblique unilateral loads applied at 1st premolar, 2nd premolar and 1st molar areas were applied. Maximum and minimum loads were calculated. Results: Under vertical loading, the maximum stresses in the glass fiber reinforced acrylic denture base half that of conventional one in central position while in canine position nearly 8% increase in the stresses. Under oblique loading, the maximum stresses in the denture base show no significant difference in the 2 models. Conclusion: These results should only be used for comparative purposes between the two denture bases and cannot be viewed as a substitute for further clinical investigation. Conclusion: These resuIts shouId onIy be used for comparative purposes between the two denture bases and cannot be viewed as a substitute for further clinical investigation