PURPOSE: To evaluate prognosis-related CT findings in hypoxic ischemic encephalopathy. MATERIALS AND METHODS: For the purpose of prognosis, 28 children with a clinical history and CT findings suggestive of hypoxic ischemic encephalopathy (HIE) were restrospectively reviewed. The diagnostic criteria for HIE, as seen on CT scanning, were as follows : 1, ventricular collapse ; 2, effacement of cortical sulci ; 3, prominent enhancement of cortical vessels ; 4, poor differentiation of gray and white matter ; 5, reversal sign ; 6, obliteration of perimesencephalic cistern ; 7, high density on tentorial edge, as seen on precontrast scans ; and 8, low density in thalamus, brain stem and basal ganglia. On the basis of clinical outcome, we divided the patients into three groups, as follows : group I(good prognosis) ; group II(neurologic sequelae), and group III(vegetative state or expire), and among these, compared CT findings. RESULTS: There were thirteen patients in group I, six in group II, and nine in group III. Ventricular collapse, effacement of cortical sulci, and prominent enhancement of cortical vessels were noted in all groups, whereas poor differentiation of gray and white matter, reversal sign, obliteration of perimesencephalic cistern, high density on tentorial edge, on precontrast scan, and low density in brain stem and basal ganglia were observed only in groups II and III. CONCLUSION: CT findings showed distinct differences between groups in whom prognosis was good, and in whom it was poor. An awareness of poor prognostic CT findings may be clinically helpful in the evaluation of patients with hypoxic ischemic encephalopathy.