Intracranial hypertension in relation to memory functioning during the first year after severe head injury. The relationship between intracranial hypertension and residual memory deficit after closed head injury was evaluated using the 6-month and 1-year neurobehavioral outcome data obtained by the Traumatic Coma Data Bank. Intracranial pressure was analyzed using the percentage of time that it exceeded 20 mm Hg and the maximum value recorded during the first 72 hours after injury. Memory measures included recall of word lists, prose recall, and visual memory for designs that were obtained 6 months (n = 149) and 1 year (n = 132) after injury. Intracranial hypertension occurred in more than half of the Traumatic Coma Data Bank cohort who met the criteria for the neurobehavioral follow-up study. Linear regression analysis disclosed an effect of elevated intracranial pressure on some, but not all, measures of memory at 6 months, whereas the results were negative for the 1-year follow-up examination. We conclude that the elevation of intracranial pressure exerts little if any effect on later memory functioning, and that any effect it does have diminishes over 1 year in survivors of severe head injury. 