Traumatic brain injury (TBI) is a major cause of morbidity and mortality in Bangladesh and also worldwide. Secondary brain injury from progressive intracerebral hematoma, increasing cerebral edema, raised intracranial pressure and subsequent cerebral ischemia is the main cause for morbidity and mortality following TBI. Secondary brain injury is worsened by post-traumatic coagulopathy, which occurs in brain injured patients and is associated with increase in risk of death and morbidity. The antifibrinolytic agent tranexamic acid (TXA) reduces the hematoma expansion and demonstrated improved clinical outcome also reduced the mortality and morbidity. This was a randomized controlled trial (RCT) done in the Department of Neurosurgery, Dhaka Medical College and Hospital. Included patients were randomized to get either the intravenous tranexamic acid (Group A) or placebo (Group B) treatment based on a computer-generated code list (50 patients in each group) along with usual medical management for traumatic brain injury. The extent of contusion expansion (hematoma plus perihematomal oedema) as the primary outcome at 48 hour after admission and was measured by brain CT scan. The contusion and oedema volume were calculated both the times (on admission and after 48 hours). Glasgow coma scale (GCS) after 48 hours and Glasgow outcome scale (GOS) after 7 days were observed. In this study showed increase in hematoma volume in both groups (p<0.05). But the increased hematoma volume in the Group A was significantly less than that in the control group. The mean total hemorrhage expansion was (1.5±1.1) ml and (4.6±1.9) ml in the Group A and Group B, respectively. In Group A- 02(4.0%) patients required operation, whereas in Group B- 11(22.0%) patients required operation. The result was significant (p=0.023) between groups. Therefore use of tranexamic acid is associated with lesser hematoma volume progression. Mean GCS (after 48 hours), mean GOS (after 7 days) result were significantly better in Group A (p<0.001). This study concluded that tranexamic acid has beneficial effect on the patient with significant traumatic brain injury. Tranexamic acid helps in reduction of intracerebral progression of contusion and improvement of clinical outcomes in patients with TBI.