Background: Acute BPCCI was previously presented only as a case report. The prognosis of acute BPCCI is related to many factors, such as gender, age, NIHSS, Hypertension and so on. We first systematically analyzed the clinical symptoms, imaging, etiology and prognosis of acute BPCCI and identified a statistically significant factor. Methods: A total of 72 acute BPCCI patients admitted to the Department of Neurology, Beijing Friendship hospital, Capital Medical University were included. The demographics, risk factors, clinical manifestations, National Institute of Health stroke scale (NIHSS) on admission, imaging findings, and the modified Rankin Scale (mRS) at the third month after onset were collected. The mRS score greater than 3 indicated poor prognosis. The factors affecting their prognosis were analyzed. Results: We included 72 Chinese patients with acute BPCCI (82% male). The most common symptoms and signs of the patients were dizziness and unilateral limb weakness. Patients with acute BPCCI involving cerebellum accounted for 85% of the patients. The number of patients with large-artery atherosclerosis was 46 (64%), the number of patients with cardiogenic embolism was 12 (17%), and the number of patients with other causes and unknown causes was 14 (19%). After multivariate regression analyses, NIHSS score (odds ratio 0.725, 95% confidence interval 0.586-0.896, P = 0.003) was closely related with the prognosis of acute BPCCI. Conclusion: Our study found that the symptoms and signs of acute BPCCI were nonspecific and mainly depended on imaging diagnosis. Acute BPCCI involving cerebellum was the most common case of acute BPCCI. The main cause of acute BPCCI was largeartery atherosclerosis. NIHSS score is identified as a statistically significant factor. The higher NIHSS score on admission showed the worse prognosis. Therefore, an acute BPCCI patient with a high NIHSS score should be paid more attention at the time of diagnosis.