Surgical fixation of the cervical spine underwent rapid evolusion. The intial goal of surgery is to provide adequate decompression of the spinal cord and the nerve roots. We had studied 50 cases with different non-traumatic causes of cervical instability, of which 35 fixed anteriorly, 14 fixed posteriorly, and one fixed by combined anterior and posterior. We found that there was a relation between the cervical curveture and the type of fixation. In cases with cervical kyphosis the posterior fixation is recommended. Also it is better to use bone grafts and anterior plate fixation in cases with multiple levels cervical discectomy to secure the fusion and place of bone graft.