Objectives: The aim of this research was to examine ‎the dimensions of axis I disorders during the first four months after ‎Traumatic Brain Injury (TBI) and mental states after TBI. Method: Overall, 238 patients (43 females and 195 males) with TBI, in a descriptive-longitudinal study, were selected by consecutive sampling procedure and each of them undergone medical ‎examinations. After 4 months of follow-up, 65.1% (155 cases) of the patients referred ‎to a psychiatrist to determine the nature of their mental disorder due to ‎TBI, using a structured clinical interview, based on the Diagnostic and Statistical Manual of Mental Disorders, 4th ed. (DSM-IV) ‎. Results: The results showed that 75.5% (117 cases) of the patients had post-injury mental disorders ‎secondary to TBI‎. Of these, 88 patients (75.2%) showed the comorbidity of mental disorders. However, the most common mental disorders due to TBI included personality change (58.6%), mood disorders (32.3%), anxiety disorders (20%), sleep disorders (19.3%), chronic amnesia (12.9%) and somatoform disorders (1.3%). Delirium, eating and psychotic disorders due to TBI, ‎each ‎up to 0.64%, were also diagnosed‎. Conclusion: The high frequency of mental disorders is evident in the acute phase after TBI, along with many novel cases of personality changes, mood and anxiety disorders. Therefore ‎‎TBI patients must be monitored and evaluated at least in a 4-‎month period after the trauma to reduce the risk of mental ‎disorders incident.