The long-term outcome of cervical spondylitic myelopathy after surgical treatment was retrospectively reviewed and critically evaluated in 100 patients with documented cervical myelopathy treated between 1978 and 1988 at our institution. Eighty-four patients were available for long-term study. The median duration of follow up was 7.35 years (range 3 to 9.5 years). There were 67 men and 17 women; their ages ranged from 27 to 86 years. The duration of preoperative symptoms ranged from 1 month to 10 years. Preoperative functional grade as evaluated with the Nurick Scale for the group was 2.1. Thirty-three patients with primarily anterior cord compression, one- or two-level disease, or a kyphotic neck deformity were treated by anterior decompression and fusion. Fifty-one patients with primarily posterior or cord compression and multiple-level disease were treated by posterior laminectomy. There was no difference in the preoperative functional grade in these two groups. The patients in the posterior treatment group were older (59 vs 55 years). There was no surgical mortality from the operative procedures; morbidity was 3.6%. Of the 33 patients undergoing anterior decompression and fusion, 24 showed immediate functional improvement and nine were unchanged. Of the 51 patients who underwent posterior laminectomy, 35 demonstrated improvement, 11 were unchanged, and five were worse. Six patients, one in the anterior group and five in the posterior group, demonstrated early deterioration. Late deterioration occurred from 2 to 68 months postoperatively. Four (12%) patients who had undergone anterior procedures had additional posterior procedures, and seven (13.7%) patients who had undergone posterior procedures had additional decompressive surgery. The final functional status at last follow-up examination for the 33 patients in the anterior group was improved in 18, unchanged in nine, and deteriorated in six. Of the 51 patients who underwent posterior decompression, 19 benefited from the surgery, 13 were unchanged, and 19 were worse at last follow up than before their initial surgical procedure. Age, severity of disease, number of levels operated, and preoperative grade were not predictive of outcome. The only factor related to potential deterioration was the duration of symptoms preoperatively. The results indicate that with anterior or posterior decompression, long-term outcome is variable, and a subgroup of patients, even after adequate decompression and initial improvement, will have late functional deterioration.