Aim and Objective: To evaluate the outcome of the poor GCS patients operated for Acute subdural hematoma with decompressive craniotomy alone vs decompressive craniotomy with cisternostomy. Materials and Methods: Fifty four consecutive cases of poor GCS of Acute SDH were operated at Medical College Hospital by decompressive craniotomy alone vs decompressive craniotomy with cisternostomy in order to assess the outcome. Observation and Results: Fifty four patients divided in 2 groups of 27 patients each consisting of 21 males and 6 females in each group were randomly selected. Mean age of the patients in group A was 42.25 years (Range: 19 - 72 years) and Group B was 50.33 years (Range: 28 - 71 years).In group A mortality was 33.33% and in group B mortality was 11.11%. Conclusion: We may conclude in our study that patients with cisternostomy with decompressive craniotomy have better prognosis than patients with decompressive craniotomy alone in view of mortality andmorbidity.