Cervical spinal trauma is one of the most frequent causes of disability. Upper cervical spinal trauma, caused by more than one mechanism, is a complex injury which may show various neurological statements. Atlantoaxial fractures are seen frequently after motor vehicle accidents and falls from height. Various treatment modalities defined in the upper cervical spine trauma and surgical treatment technique, so there is still unclear. Seven patients, six male and one female, were surgically treated for symptomatic atlantoaxial instability. The major cause of instability was; motor vehicle accident in six patients and falling from height in one patient. C1-C2 posterior fixation and posterolateral fusion was performed in 7 cases. The fusion and C1-C2 stability were achieved in all cases after 6 months. C1-C2 posterior fixation and fusion technique is a reliable and safe method to treat atlantoaxial instability when followed the given instruction by spinal surgeons. But, further prospective clinical studies will be needed to determine the effectiveness of this technique