Aim: Intraradicular post systems have become an important treatment method for endodontically treated teeth as they provide retention for restoration to the remaining tooth structure. The objective of the present in vitro study was to evaluate the effect of different fiber post-application techniques on the fracture resistance of premolars with flared root canals and no ferrule. Materials and Methods: Sixty freshly extracted, single-rooted mandibular premolars with no ferrule were endodontically treated by an experienced endodontist, and their root canals were experimentally flared. The specimens with flared root canals were divided into five groups according to fiber post-application techniques (n = 12): a prefabricated fiber post (G1), G1 + two auxiliary posts (G2), i-TFC post system (G3), G1 + quartz splint (G4), and Ribbond (G5). The data were analyzed with analysis of variance and Tukey tests. Results: The findings were revealed that no significant difference was found among four groups, except G5 (P >.05), which demonstrated the lowest fracture resistance (P <.05). G2, G3, G4, and G5 exhibited dominantly restorable fracture pattern, whereas G1 exhibited nonrestorable fracture pattern. Conclusion: Within the limitations of this study, the placement of auxiliary posts, i-TFC post system, quartz splint placement, and Ribbond increased the incidence of restorable fracture compared with the controls.