Twenty-four patients with hypoxic-ischemic encephalopathy were examined with serial magnetic resonance imaging up to 4 years of age. Magnetic resonance imaging studies were performed in the neonatal period, at the fourth month and the fourth year of age, and the findings were compared with the patients' neurodevelopmental outcome at the fourth year of age. Periventricular signal alterations and deep gray matter involvement were usually evident in the initial magnetic resonance imaging studies, and encephalomalacia, periventricular leukomalacia, and atrophy were the common findings on follow-up magnetic resonance imaging studies. In the patients with hypoxic-ischemic encephalopathy, some correlation between magnetic resonance imaging findings and neurodevelopmental outcome was recognized. The patients with deep gray matter involvement on the initial magnetic resonance imaging had a poor prognosis, and the ones with normal magnetic resonance imaging findings had a favorable neurodevelopmental outcome. On the follow-up magnetic resonance imaging findings, encephalomalacia and periventricular leukomalacia were associated with poor neurodevelopmental outcome. In predicting the neurologic outcome at 4 years of age, magnetic resonance imaging findings of the neonatal period had the highest negative predictive value, whereas magnetic resonance imaging findings at 4 months of age and 4 years of age had the highest positive predictive value.