Objective To explore the useful value of enhanced multi-slice CT (MSCT) and three-dimensional post processing technique in diagnosis of vertebral arterial insufficiency due to cervical spondylosis. Methods Sixty-three patients accepted contrast-enhanced MSCT examination. Thirty cases with no vertebral arterial insufficiency also performed the same scanning as a control group. The three-dimensional post processing images of two groups were analyzed and compared. Results Among 63 cases, vertebral artery showed normal in 11 cases, bilateral vertebral artery abnormal in 2 patients, unilateral vertebral artery thin in 38 cases, local stenosis of vertebral artery in 7 cases and obstruction in 5 cases. For control group of 30 cases, vertebral artery showed normal in 23 cases, unilateral vertebral artery thin in 7 cases. There was statistically significant difference between two groups in vertebral artery normal and thin, respectively ( P 0.05). Bilateral transverse foramen showed symmetrical and normal in size in 24 cases (38%), only unilateral transverse foramen smaller in 36 cases (57%). In control group, bilateral transverse foramen showed symmetrical and normal in size in 22 cases (73%), right transverse foramen smaller in 5 cases (17%). Significant difference existed between study group and control group in transverse foramen changes in size ( P 0.01). Conclusion Contrast-enhanced MSCT scanning and three-dimensional post processing images can show clearly changes of vertebral artery and bone structures. It possesses the important value in diagnosis of vertebral arterial insufficiency due to cervical spondylosis.