Background:The present study was conducted to investigate the role of amantadine in traumatic brain injury for cognitive function improvement. Materials and methods:A total of 300 patients were included in the study who were randomly divided into two groups: AMH group and placebo group. The drug was administered for 6 weeks. Patients were evaluated on the first day (day of starting AMH), after 7 days and after 3 months from starting drug with GCS score, KPS score, DRS score and MOCA score. Results:The GCS, KPS and DRS scores were significantly improved in AMH group after 3 months (p=0.034, 0.006 and 0.011 respectively). The MOCA score was significantly higher in Amantadine group after 7 days and after 3 months (p=0.033 and 0.038respectively). The change of MOCA score from day 1 to day 7 and day 7 to 3 months were significantly greater in Amantadine group (p=0.029 and p=0.046 respectively). Conclusion:Amantadine produced significant effects in the improvement of the patients’ cognitive function with respect to GCS, KPS, DRS and MOCA scores.