Objective To evaluate the clinical effects and safety of polymyxin B on ventilator-associated pneumonia caused by pandrug-resistant Acinetobacter baumannii (PDR-AB) in patients with chronic obstructive pulmonary disease (COPD). Methods COPD patients who were diagnosed as ventilator-associated pneumonia caused by PDR-AB and treated with polymyxin B between January 2015 and August 2016 in this hospital were included in this retrospective study. The patients’ symptoms, vital signs, and the results of laboratory examinations were recorded before and after treatment. The clinical cure rates, microbiological eradication rates, mortality and safety were also measured. Results A total of 11 cases were included in this study. Mean time of therapy was 10 days, ranged 8-13 days. After treatment with polymyxin B, most of the patients’ clinical symptoms, signs, and results of laboratory tests as well as imaging examinations were significantly improved. Seven cases had clinical response, and the clinical efficacy rate was 63.6%; 8 cases achieved bacteriological eradication, with the bacteriological eradication rate of 72.7%. Four patients died, and the overall mortality was 36.4%. Only 1 case discontinued treatment with polymyxin B because of the drug fever. Conclusions Polymyxin B might be an alternative option for COPD patients with ventilator-associated pneumonia caused by PDR-AB, who is non-responder to prior antimicrobial therapy. However, this method should be evaluated cautiously in prospective well-controlled studies.