Aim: this study was designed to investigate the fracture resistance of endodontically treated teeth when restored with a new resin endodontic system (RealSeal) in comparison to non metallic customized posts (EverStick fiber-reinforced post system and high strength ceramic (zirconia) post and core system). Materials and Methods: a total of fifteen freshly extracted maxillary central incisors, free of cracks, fracture or caries and with approximate dimensional similarity were selected. Teeth were sectioned horizontally 3 mm above the most coronal point of the cemento-enamel junction proximally. Teeth were divided into 2groups. Group A: Ten teeth were obturated with gutta-percha and resin sealer, and then subdivided into 2 groups each five teeth restored with different post. Group B: Five teeth obturated with Resilon cones (without post) (RealSeal)). The tested samples according to its restorative techniques were: group (1): 5 Teeth restored with customized fiber post (EverStick). Group (2): 5 Teeth restored with customized Zirconia post-core. Group (3): 5 Teeth restored with RealSeal system. The tooth blocks were designed to simulate natural tooth condition including periodontal ligament and gingival attachment level. Samples were prepared under standardized conditions. Posts were cemented with self adhesive resin cement (SmartCem2) in group (1&2). In Group (1&3) dual cure fiber reinforced composite cores (Build-It) were fabricated in standardized dimensions. IPS e.max Press crowns were fabricated for all samples and cemented with self-adhesive resin cement (SmartCem2). All samples were tested using a universal testing machine at crosshead speed of 0.5 mm/min at 135˚ angle until failure. The fracture patterns were evaluated visually and microscopically. Results: results of this study revealed that the highest mean fracture resistance value was recorded by the RealSeal group (430.5 ± 133.7 N) followed by Zirconium post group (422.7 ± 119 N), while the lowest value was for the EverStick post group (395.3 ± 102.2 N). However, one-way ANOVA test did not show any significant differences in fracture resistance among the groups (P-value = 0.887). Visual examination reveled that both groups (1 and 3) had 100% favorable fracture while in group (2) had 40% favorable and 60% unfavorable. In microscopic examination 100% of the samples in group (2) showed cracks all over the roots. Conclusions: Using of posts for the anterior endodontic treated teeth with 2 mm ferrule does not increase its fracture resistance. The results of the RealSeal and customized fiber-reinforced composite posts and composite core were promising as treatment option for anterior endodontically treated teeth with 2 mm ferrule. The micro-cracks finding could make us conclude that failed zirconium post restored teeth should be considered as unfavorable even though the clinical appearance would denote otherwise.