Cerebrospinal fluid lactate and intracranial pressure were measured in 24 severely head-injured patients with Glasgow coma scale below 8. Cerebral perfusion pressure, vital sign and CVP were also measured simultaneously. Severely head-injured patients revealed increased CSF lactate and intracranial pressure which have been significantly correlated with outcome. But changes of vital sign, cerebral perfusion pressure and CVP were not correlated with outcome. The elevation of intracranial pressure checked on arrival was statistically significant in correlation to outcome. And the elevation of CSF lactate were correlated with statistically significance in correlation with outcome and lactate level checked on time interval(arrival, 12hr, 24hr, 48hr after trauma). And so CSF lactate levels are statistically more significant than intracranial pressure in predicting prognosis. We will expect good prognosis in severely head-injured patient by reducing intracranial pressure and CSF lactate, oxygenation and increasing cerebral perfusion.