Objective:To analyze high-risk factors for poor neurological prognosis in full-term neonatal purulent meningitis based on clinical and brain MRI features.Methods:This study was a case-control study. The clinical and brain MRI data of 79 neonates with purulent meningitis were retrospectively collected at Beijing Children′s Hospital, Capital Medical University from January 2016 to January 2022. Follow-up assessments including growth and development, as well as neurological sequelae, were conducted over a minimum follow-up period of 6 months. The patients were divided into two groups with good ( n=49) and poor prognosis ( n=30) according to follow-up results. Chi-square tests were used to compare clinical and brain MRI features between the two groups, and a multivariate logistic regression analysis was performed to explore the high-risk factors for poor neurologic prognosis in full-term neonates with purulent meningitis. Results:There were statistically differences between two groups regarding the incidence of seizures, early-onset manifestations, positive cerebrospinal fluid (CSF) culture, CSF white cell counts, and CSF protein concentration ( P<0.05). Statistically differences were also found in the occurrence rates of ependymitis, obvious ventricular dilatation/hydrocephalus, spotty and patchy brain injury/hemorrhage, and destructive lesions within the brain parenchyma ( P<0.05). The results of multivariate logistic regression analysis indicated that seizures ( OR=5.722, 95% CI 1.126-29.072, P=0.035), early-onset neonatal purulent meningitis ( OR=3.657, 95% CI 1.073-12.459, P=0.038), ependymitis ( OR=8.851, 95% CI 1.169-67.017, P=0.035), obvious ventricular dilatation/hydrocephalus ( OR=12.675, 95% CI 1.085-148.110, P=0.043), and destructive lesions within the brain parenchyma ( OR=16.370, 95% CI 1.575-170.175, P=0.019) were independent risk factors for poor prognosis. Conclusions:The occurrence of seizures, early-onset manifestations as well as ependymitis, obvious ventricular dilatation/hydrocephalus, and destructive lesions within the brain parenchyma on MRI are high-risk factors for poor prognosis in the full-term neonate with purulent meningitis.