OBJECTIVE: Massive intracerebral hemorrhage (ICH) is devastating neurosurgical disease. Decompression surgery has been performed to manage the uncontrolled increased intracranial pressure and good clinical result has been reported. Authors analyze the ICP trend after the decompression surgery and report the clinical usefulness. METHODS: Thirty patients data with massive ICH were analyzed retrospectively. Surgical indication was constantly followed in these patient ; Glasgowcoma scale score less than 8, midline shift more than 6 mm on brain CT. In all patients ventricular puncture was done before the decompression and monitored the ventricular pressure changes during and after the surgery. RESULTS: In massive ICH patients, the ICP was maintained in physiological range if the hematoma was removed more than 80%. And when we tried additional therapies like hypothermia or coma therapies in another group, the ICP was elevated at the time of the additional therapy. CONCLUSION: From this study, if the ICH removed more than 80% and The ICP was not exceed 20 mmHg during the first post-operation day, the ICP hardly exceed 20 mmHg after than. Authors thought that decompression surgery is not an essential treatment for the massive ICH patient if their hematoma removed enough.