Objective To analyze the safety and effectiveness of using lumbar drainage (LD) in patients with subarachnoid hemorrhage (SAH).Methods Data from 44 patients with SAH were collected.Of these patients,the LDs group consisting 19 patients in whom a lumbar drain had been placed for cerebro-spinal fluid (CSF) drainage,whereas the control group was composed of 25 patients who received no form of CSF drainage or treated solely with an external ventricular drainage (EVD).Incidence of new cerebral infarction of the two groups was measured on sequential CT and complications of LDs group.Results This retrospective review demonstrated a statistically significant beneficial effect in LDs group on CT,reducing the incidence from 32％ to 5％.A similar degree of benefit was observed in two group patients with hydrocephalus.Complications with lumbar drains were rare and yielded no permanent sequelae.Conclusion With rare complications and definite safety,LDs are effective to reduce vasospastic cerebral infarction of SAH patients when appropriate patient selection and good technique are employed.