Purpose: The purpose of the present study was to evaluate the push out bond strength of the composite resin core to prefabricated esthetic posts, while varying the treatments applied to the post surface. Materials and methods: A total of forty prefabricated post specimens were used in this study. Based on the post type were divided into 2 groups. Group I: fiber posts (Easy Post n=20), and Group II: zirconia posts (Cosmo post n=20). Each group was subdivided into four subgroups according to post surface pretreatment. (Each subgroup contains 5 posts). nano- composite (FiltektmZ350XR) (diameter 8 mm; height 6 mm ) were buildup over the treated posts surface using special mould. Push out bond strength was carried out using compressive loading via a computer controlled testing machine and data were recorded using computer software. Scanning electron microscopy was employed to examine the bonding surfaces after the push out bond strength tests. Result: Comparing Effect of different surface treatment in the same group, in group I (Easy post) It was found that silica coated subgroup recorded the highest push out bond strength mean value ±3.2 followed by air abraded subgroup ±1.7 then 10 % H2O2 solution treated subgroup ±3.05 while non-treated subgroup recorded the lowest mean value ±0.32.While in Group II: (Cosmo post) It was found that silica coated subgroup recorded the highest push out bond strength mean value ±3.4 followed by air abraded subgroup ±1.5 then hot etch solution treated subgroup ±3.1 while non-treated subgroup recorded the lowest mean value ±0.92 .Two ways ANOVA comparing the variables affecting bond strength test results: regardless to post type, totally it was found that surface treatment revealed significant (p<0.05) influence on bond strength mean values (Silica coat ≥ Air Abrasion > 10% H2O2 > Hot etch solution > no treatment). Conclusions: Within the limitations of this study, the bond strengths of the composite resin core to prefabricated esthetic posts vary significantly in accordance to the method of surface treatment used. Surface treatment is more effective with fiber posts than with Zirconia posts Based on the push out bond strength results, fiber and zirconia posts treated with the CoJet system resulted in the highest bond values.