Type II odontoid fracture is a common upper cervical spine injury in elderly patients and remains challenging to manage. The odontoid process is located within a vascular watershed zone, and fracture healing in older patients is frequently compromised by reduced bone quality and diminished blood supply. As a result, conservative treatment with prolonged external immobilization is associated with a substantial risk of nonunion, while extended use of rigid collar or sterno-occipital-mandibular orthosis may further contribute to pain, deconditioning, and functional decline. A minimally invasive surgical strategy that provides sufficient stability while minimizing muscle dissection and associated perioperative morbidity is therefore appealing in elderly patients with limited physiological reserve. We describe a full-endoscopic posterior atlantoaxial fixation technique and report early clinical and radiographic outcomes. Two patients, both 62 years of age, with acute type II odontoid fractures underwent endoscopic posterior C1–C2 instrumentation. The procedure was performed through a muscle-sparing posterior approach using an approximately 2-cm skin incision. Under continuous endoscopic visualization, atlantoaxial screw–rod fixation was achieved with minimal disruption of posterior musculature, aiming to provide immediate segmental stability while limiting surgical trauma. Operative time, blood loss and perioperative complications were recorded. Clinical outcomes were assessed using the visual analog scale (VAS), Neck Disability Index (NDI), SF-36, and cervical range of motion. Radiographic evaluation focused on fracture alignment, implant position, and fracture healing using postoperative imaging and follow-up computed tomography. Endoscopic atlantoaxial fixation was successfully completed in both patients without neurological deterioration or procedure-related complications. Intraoperative blood loss was minimal. Postoperative imaging demonstrated satisfactory alignment and stable instrumentation. At 3 months of follow-up, computed tomography confirmed fracture union in both cases. Clinically, both patients experienced marked improvement in pain and functional scores and were able to resume daily activities without prolonged external immobilization. These preliminary findings suggest that endoscopic posterior atlantoaxial fixation is technically feasible and may provide sufficient stabilization for type II odontoid fractures in elderly patients while minimizing perioperative morbidity. This minimally invasive approach may represent a practical surgical option in carefully selected cases.