Abstract: Endodontically treated teeth with extensive coronal destruction require a post and core to retain the definitive restoration, and the elastic modulus of the post material influences the risk of root fracture. Polyetheretherketone (PEEK), a metal-free thermoplastic polymer with a modulus close to that of dentin, combined with CAD/CAM technology, offers a promising alternative for custom-made post and cores. This case report describes the clinical procedure for fabricating a customized one-piece PEEK post and core using CAD/CAM technology and highlights its bonding and esthetic challenges. A 14-year-old male patient presented after dental trauma with a horizontal coronal fracture of the maxillary right central incisor, associated with a Class II skeletal pattern, a 6 mm overjet and overbite, and interdental diastemas. Since composite restoration would have been non-retentive, a corono-radicular reconstruction was planned after endodontic treatment, followed by a PMMA provisional prosthesis supported by the tooth until a definitive fixed prosthesis at age 20. An indirect technique was used: gutta-percha was partially removed, the canal was shaped, and a silicone impression was scanned to design and mill the post and core from a PEEK blank. The restoration was bonded in the same session with a self-etching universal adhesive and an MDP-containing resin cement, and the provisional crown was sealed. PEEK showed favorable biomechanical behavior, with an elastic modulus (5 GPa) lower than that of dentin, but its inert surface compromises adhesion and its opacity limits anterior esthetics, which may be compensated by a translucent ceramic final restoration. Milled PEEK posts represent a solid clinical option, although improved bonding protocols, optical properties, and long-term clinical trials remain necessary.