Head Injuries due to traffic accidents are now the leading cause of death and long term disability in males between 30-50 years. Many patients with head injuries experience mild dysfunction of cognition without major neurosurgical problems, and this may interfere with successful rehabilitation. However, not many studies have been done to investigate the cognitive functioning following mild head injuries. The purpose of this study was to obtain injured patient's demographic data including medical, neuropsychological and social data, and to investigate the cause of injury and alcohol use at the time of injury. This study focused on the recovery of cognitive function in patients with head injuries and used the Mini Mental State Examination(MMSE) score and its correlation with demographic and social data. Data on 77 patients with minor head injuries who were admitted to the department of Neurosurgery in C and E hospital in Dae Jun from September 1991 to February 1992 were analyzed. The findings of this study are as follows ; 1) Out of the 77 cases reviewed in this study, 62 were male, 15 were female. 2) A higher incidence of injury was observed between 7:00 PM and 12:00 PM. 3) The most common cause of head injury in traffic accidents was pedestrian accidents, and the next most frequent cause was most motorcycle accidents. 4) Thirteen of the 77 cases in this study were under the influence of alcohol at the time of injury, and they were all male. 5) The MMSE scores one month after injury and at discharge were significantly lower in patients with head injuries that included skull fractures than in patients without skull fractures, suggesting lower cognitive function in patients with skull fractures. 6) The level of consciousness at admission and three days after admission measured by the GCS for drivers under the influence of alcohol was lower than for sober drivers. The MMSE score was also lower for drunken drivers. 7) The MMSE score one month after the injury had a reciprocal relationship with the age of the patient. 8) The MMSE score one month after the injury had at discharge were highly correlated with the duration of unconsciousness. 9) The MMSE score one month after injury and at discharge were highly correlated with the GCS scores at admission, three days after admission, and one week after admission.