Optic nerve sheath diameter measured by using ultrasound and its correlation with midline shift and outcome are independent predictors in patients with traumatic brain injury. Patients who satisfy the inclusion criteria were subjected to CT scan at admission, immediately after surgery and at discharge. With each CT scan, the corresponding optic nerve sheath diameter is measured 3mm behind the eye ball bilaterally and the mean value calculated using ultrasound.44 patients were included. On admission there were 47.7% abnormal ONSD measurements, and 52.3 % normal ONSD measurements taking cut off of ONSD as 4.5mm as normal. There was reduction in ONSD after surgery , the percentage reduction being from 47.7% to 26.7% after surgery and from 26.7% to 11.9% at the time of discharge. Higher ONSD was observed in patients with moderate and severe brain injury. ONSD showed a direct relationship with CT findings measured in terms of midline shift and inverse relationship with outcome. ONSD could serve as an initial tool in predicting the outcome of patients with raised intracranial tension