In severe head injuries, delayed intracerebral hematoma appearing lately is noted due to the spread use of serial CT scan. The authors experienced the autopsy of 5 cases who presented diffuse axonal injury (DAI) among these new lesions in repeated CT scan findings and report the pathohistological findings. Subjects were as follows: The age range of the patients was 15 to 25 years. The consciousness levels of the 5 cases on admission were 6 or less by the Glasgow coma scale. CT findings of DAI were revealed hemorrhage of the corpus callosum, basal ganglia, tegmentum of pons, intraventricular, and acute brain swelling. Total clinical courses were 2 to 29 days, but most of them were 9 or less days. In the macroscopic findings, marked congestion and edema revealed mainly in deep part of the white matter of the frontal lobe in all 5 cases. Callosal disruption and hematoma adjacent the corpus callosum revealed in 4 out of 5 cases. Cerebral contusion with hemorrhage revealed in 3 out of 5 cases. Intraventricular hemorrhage and traumatic subarachnoid hemorrhage revealed in 2 out of 5 cases. Hemorrhage of basal ganglia and base of pons revealed in 2 cases. Microscopic examination of all 5 cases revealed pallor of myelin in the corpus callosum and white matter surrounding hemorrhagic lesion, and abnormal tortuous, swelling and fragmentation of axons in stained preparation. Axonal retraction ball was recognized in 3 out of 5 cases. In conclusion, five autopsied cases who presented acute brain swelling and hemorrhage of corpus callosum and tegmentum of pons in serial CT scan were examined.(ABSTRACT TRUNCATED AT 250 WORDS)