Objective: This study was carried out to compare themaximum bite Force of diabetic patients wearing two different types of removable partial dentures; heat cured acrylic and flexible denture base.The patients were controlled type 2 diabetes mellitus patients(T2DM) having maxillary and mandibular bounded posterior edentulous span(Class III Kennedy classification) opposing each other during different time intervals. Materials and Methods: thirty controlled type 2 diabetic patient having maxillary and mandibular posterior bounded edentulous span (Class III Kennedy classification) opposing each other were selected. Maximum bite forces (MBF) were measured for both polymethyl methacrylateheat cure resin (PMMA) and thermoplastic acrylic removablepartial denture by using a portable force gauge. Records were taken one day after delivery, one month and 2 months later for each partial denture. Results:MBF for thermoplastic denture was significantly higher than PMMA denture (P < 0.05) as in PMMA denture it was (27.2 ? 3.8, 30.6 ? 4.04, 35.4 ? 4.7) while in thermoplastic denture it was (55.4 ? 5.9, 60.2 ?4.1 & 67.6 ?5.1) after delivery, one month and 2 months later respectively. Conclusion: The thermoplastic acrylic partial dentures showed higher maximum bite force than the polymethyl methacrylate heat cure acrylic partial dentures in all recorded time intervals and the maximum bite force was increased in both dentures with increasing the adaptation period.