Background: The bacterial resistance rate has risen in recent years, and polymyxin B has been used more frequently to treat severe intracranial infection. This study aimed to investigate the clinical efficacy and safety profiles of intraventricular polymyxin B plus continuous ventricular drainage for the treatment of intracranial infection caused by drug-resistant Acinetobacter baumannii (DR-AB). Methods: A retrospective study was performed on 21 patients who had an intracranial infection caused by DR-AB after neurosurgery at our hospital from May 2017 to July 2020. These patients were treated by intraventricular polymyxin B plus continuous ventricular drainage. The clinical features, treatment, cerebrospinal fluid (CSF)-related indicators, outcomes, and prognosis of these patients were analyzed. Results: The external drainage tubes inserted into the lateral ventricle were kept unobstructed in all 21 patients. These patients received intraventricular polymyxin B 5 mg/day plus intravenous antibiotics. The treatment with intraventricular polymyxin B lasted for 18.19±12.36 days. The time to positive CSF culture was 10.50±10.60 days. The bacterial clearance rate of CSF was 95.2% (20/21). The clinical cure rate was 81.0% (17/21), and the mortality rate was 19.0% (4/21).As for the causes of death, 1 case died from purulent CSF with cerebral abscess, which was considered to be caused by extensive brain parenchymal infection, 2 cases died from spontaneous intraventricular hemorrhage after returning negative for CSF cultures, and 1 case died from secondary massive cerebral infarction after returning negative for CSF cultures. There were no significant changes in the serum creatinine level before and after treatment.Conclusions: For intracranial infection caused by DR-AB, early intraventricular polymyxin B plus continuous ventricular drainage could effectively clear the drug-resistant bacteria from CSF, thereby improving efficacy and reducing mortality. Renal functions before and after treatment were not changed significantly, proving that this combined treatment was safe and effective.