Abstract: Polyetheretherketone (PEEK) has emerged as a thermoplastic material of choice in the realm of implantable medical devices, owing to its high biocompatibility and exceptional mechanical strength. Despite its promise for custom-made medical devices, 3D-printed PEEK in orthopedics, trauma, and spinal implants has not yet achieved widespread application. This study outlines the properties of PEEK, 3D-printed PEEK-based composites, and their utilization in implantable medical devices, thereby fostering the development and regulation of next-generation medical devices.