A randomized clinical trial was conducted to asses the effects of dexamethasone on brain oedema following acute ischemic stroke in the departments of Medicine of different hospitals from July, 2003 to December, 2006. A total of 60 patients were included in the study. They were divided into two groups keeping the similarity regarding the age, sex and severity of the stroke between two groups. There were 30 patients in experimental group and 30 in control group. The level of consciousness was compared by Glasgow Coma Scale (GCS) on 3rd, 7th and 10th day of intervention and improvement was found in both the groups, but the improvement of level of consciousness was statistically significant in Dexamethasone treated group. The volume of hypodense area did not differ significantly in two groups in CT scans before and after treatment (p=0.74). The study results demonstrate that Dexamethasone improves the level of consciousness in acute ischemic stroke associated with brain oedema but did not reduce volume of hypodense area.