Background Increased meningitis caused by extensively drug-resistant bacillary presents a significant challenge in antibiotic selection.The aim of our study was to evaluate the efficacy and safety of polymyxin in the treatment of post-neurosurgical meningitis due to the extensively drug-resistant bacillary in children.Methods We performed a retrospective study on post-neurosurgical meningitis caused by the extensively drug-resistant bacillary in children,who were treated with polymyxin for ≥ 3 days.Results Among five post-neurosurgical meningitis cases that were included,the children were infected by Acinetobacter baumannii (n =3),Klebsiella pneumonia (n =l),and Pseudomonas aeruginosa (n =1).The drug susceptibility test showed that they were extensively drug-resistant bacillary.Two patients received intravenous polymyxin E.Three children received intravenous combined with intraventricular injection of polymyxin B.One patient infected by Klebsiella pneumonia eventually died of septic shock.No serious adverse effects of polymyxin were observed.Conclusions Polymyxin is a safe and effective therapy for post-neurosurgical,multidrug-resistant bacillary meningitis in children.