Neonatal encephalopathies following birth asphyxia are the first features of cerebral insult. They never miss when asphyxia is directly involved in cerebral impairment. Mild encephalopathies have constantly a good prognosis. Conversely, moderate and severe encephalopathies are associated with poor outcome (death or severe handicap) in 25% to 100% of cases. Prognosis of these moderate and severe encephalopathies can be assessed during the first ten days of life by 3 complementary ways: clinical exam, electrophysiology and imaging. The most information is obtained from the EEG and MRI which together nearly reach 100% for both predictive positive and negative values for severe neurological sequelae.