Background: Considering the role of Intracranial Pressure Amplitude [AMP(ICP)] in evaluating the rate of craniospinal compliance (CC) and intracranial pressure (ICP) and in estimating the degree of brain damage, the aim of the present study was to evaluate the correlation of AMP(ICP) with the degree of brain damage in patients with traumatic brain injury (TBI). Methods: Thirty-four patients were enrolled in the present study. Patients underwent intraventricular ICP monitoring. During the first 24 hours, AMP(ICP) was recorded every hour, and its total mean was calculated. Correlation of AMP(ICP) and Glasgow outcome scale (GOS) was analyzed. Results: There was a negative correlation between mean AMP(ICP) within 24 hours and GOS values on the first, third, and sixth month (r = -0.476, -0.563, and -0.627, respectively). Conclusions: The findings of the present study suggest that AMP(ICP) index can determine GOS in patients with TBI.