BACKGROUND: Hypoxic-ischemic encephalopathy (HIE) is still associated with death and sequelae including cerebral palsy and intellectual disability despite induced hypothermia. Biomarkers, as early predictive indicators of adverse outcomes, are lacking. AIMS: To investigate whether post-rewarming cerebrospinal fluid (CSF)-neuro-specific enolase (NSE) levels after hypothermia are associated with neurodevelopmental outcomes at age six years, alone or when combined with amplitude-integrated electroencephalography (aEEG) and brain magnetic resonance imaging (MRI), as neuroimaging and neurophysiological indicators, respectively. PARTICIPANTS: We retrospectively enrolled 157 patients with HIE from 2011 to 2018 with available post-rewarming CSF-NSE levels and developmental tests at age six years. Of these, 148 met the inclusion criteria, and 87 were evaluated in the final analysis. OUTCOME MEASURES: Multivariate receiver operating characteristic analysis determined the predictive ability of post-rewarming CSF-NSE levels for adverse outcomes including death and cerebral palsy, intellectual disability, and borderline disability at age 6 years either singly or in combination with aEEG and MRI findings, using logistic regression analysis. RESULTS: The cut-off value for CSF-NSE at a median 5 days after birth was 233 ng/dL (area under the curve 0.97, 95 % confidence intervals of 0.93-1.00, sensitivity 1, specificity 0.94) for death. Regarding cerebral palsy and intellectual disability, the combination of abnormal aEEG at 72 h, moderate-severe MRI injury findings, and with or without CSF-NSE (cut-off value: 55 ng/mL), odds ratio (95 % confidence intervals) improving from 8.6 (2.7-27.8) to 12.4 (3.5-43.9) (p <
0.01). CONCLUSIONS: In patients with HIE, post-rewarming CSF-NSE levels were associated not only with death independently but with cerebral palsy and intellectual disability in combination with EEG and MRI findings.