Objective: To evaluate the feasibility, safety and efficacy of atlas pedicle screws system fixation and fusion for the treatment of upper cervical diseases. Methods: Twenty-three consecutive patients with up-per cervical disorders requiring stabilization, including 19 cases of atlantoaxial dislocation (4 congenital odontoid disconnections, 6 old odontoid fractures, 4 fresh odontoid fractures of Aderson Ⅱ C, 3 ruptures of the C1 transverse ligament, and 2 fractures ofC1), 2 cases ofC2 tumor (instability after the resection of the tumors), and 2 giant neurilemomas of C2-C3(instability after resection of the tumors), were treated by posterior fixation and fusion with the atlas pedicle screw system, in which the screws were inserted through the posterior arch of Cr The operative time, bleeding volume and complications were reported. All patients were immobilized without external fixation or with rigid cervical collars for 1-3 months. All patients were followed up and evaluated with radiographs and CT. Results: In the 23 patients, 46 C1 pedicle screws, 42 C2 pedicle screws and 6 lower cervical lateral mass screws and 2 lower cervical pedicle screws were placed. The mean operative time and bleeding volume was 2.7 hours and 490 ml respectively. No intraoperative complications were directly related to surgical technique. No neurological, vascular or infective complications were encountered. All patients were followed up for 3-36 months (average 15 months). Firm bony fusion was documented in all patients after 3-6 months. One patient with atlas fracture showed anterior occipitocervical fusion. There was no implant failure. Conclusions: Posterior fixation and fusion of the atlas pedicle screw system is feasible and safe for the treatment of upper cervical diseases, and may be applicable to a larger number of patients.