Objective To study the clinical value of 128 slice spiral CT angiography of head and neck in evaluation of carotid artery stenosis in patients with acute cerebral infarction. Methods Fifty-eight patients with acute cerebral infarction admitted in our hospital from March 2010 to March 2013 were chosen as the observation group. Another 58 patients without acute cerebral infarction who were treated during the same period were included in the control group. Both of the two groups were performed 128 slice spiral CT angiography of head and neck. According to the images obtained, the degree of carotid artery stenosis and distribution of bilateral carotid artery plaques were compared between the two groups. Results The repeat diagnosis found that 81.03% of the patients in the observation group with carotid artery stenosis which was significantly higher than 48.28% in the control group (P<0.05). The proportions of mild stenosis and moderate stenosis (44.83%, 24.14%) were significantly higher than those in the control group (25.86%, 10.34%) (P<0.05). The total detection rate of plaque in the observation group (71.78%) was significantly higher than that in the control group (54.45%) (P<0.05). Conclusion In clinic, the application of 128 slice spiral CT angiography of head and neck can evaluate carotid stenosis in patients with acute cerebral infarction more effectively. The detection rate in bilateral carotid artery plaque is higher. It plays an important role in the diagnosis of acute cerebral infarction. It is of application and promotion value.