Objective: This study compared the fracture resistance of endodontically treated premolar restored with two different resin composites and dentin bonding systems. Methods: Seventy extracted human maxillary premolars were used. Five sound teeth were used as positive control group. Access and Class II MOD cavities were prepared on sixty-five teeth, and the canals were instrumented with K-files to an apical size 35 using step-back technique. All cavities were based with Vitremer 2 mm thick up to the level of the CEJ. Five preparations were used as negative control group. Sixty-prepared teeth were randomly divided into 4 groups (n=15) and restored as follows: Filtek Supreme with Single Bond, Filtek Supreme with Adper Prompt, Filtek Z250 with Single Bond and Filtek Z250 with Adper Prompt. All teeth were stored in water at room temperature for 7 days and thermocycled 90 times between 5±2°C for 30sec. and 55±2°C for 30sec. Teeth were mounted in autopolymerizing resin block and were loaded occlusally by universal testing machine with steel round cross head speed 1mm/min until fracture occurred. Results: The mean resistances (SD) of group 1, 2, 3, 4, positive and negative controls were 1921 (247)N, 1361 (93)N, 2030 (222)N, 1566 (155)N, 3289 (457)N and 698 (80)N, respectively. Statistical analysis of the data was accomplished using two-way ANOVA and Bonferroni test. Group 3 showed the highest fracture resistance followed in order of decreasing resistance by group 1, 4 and 2. Filtek Z250 showed significantly higher fracture resistance than Filtek Supreme (p<0.001). Single Bond showed significantly higher in resistance to cusp fracture than Adper Prompt (p<0.001). Conclusion: This would suggest that Hybrid composite (Filtek Z250) with Total - etch system (Single Bond) could satisfactorily be used to restore teeth after endodontic therapy.