Head injury is brain injury caused by trauma to the head. A growing literature on the varied structural pathology of the brain emphasizes both macroscopic & microscopic changes in personality. The main objectives of the study are: To find out the prevalence of head injury and the largely affected age group. The demographical characteristics & injury related information clearly indicated that most of the cases were young males and the most common reason of injury was RTA (road traffic accident). The high incidence rate of head injury emphasizes to look into reasons as how to reduce the risk factors e.g. using bicycle helmets and seat belts. And to examine post-onset cognitive deficits and personality / behavioral changes in head-injured patients. The most commonly reported deficits by the caregivers were antisocial behaviour, memory deficits and dependency problems. Significant correlation was found on various aspects of behavioural changes and cognitive deficits. Age emerged as a significant predictor of physical, language and dependency problems in head injured patients .Findings have important implications for the neuropsychological rehabilitation of head injured pattients.