ObjectiveTo assess the effectiveness and safety of continuous lumbar drainage of cerebrospinal fluid for subarachnoid hemorrhage (SAH). MethodsThe Cochrane Library (January 1992 to May 2013), Medline (January 1950 to May 2013), SinoMed (January 1979 to May 2013), CNKI (January 1979 to May 2013), and Wanfang Database (January 1979 to May 2013) were searched for randomized controlled trials (RCTs) on continuous lumbar drainage for SAH. The method of Cochrane systematic review was used to evaluate all the included RCTs. ResultsTwelve RCTs (857 patients) met the inclusion criteria, but the general methodological quality of trials was poor. Only two studies addressed the outcomes about SAH patients' death, vegetative state or disability and other adverse events at the end of the follow-up period (at least 3 months). Meta-analysis of fatality showed a better effect of lumbar continuous drainage of the cerebrospinal fluid for SAH than the control group with statistical significance [RR=0.27, 95%CI (0.12, 0.59), P=0.001]. Meta-analysis of complications also showed a better effect of lumbar continuous drainage of the cerebrospinal fluid for SAH than the control group with statistical significance (except re-bleeding) [cerebral vasospasm: RR=0.20, 95%CI (0.14, 0.30), P<0.000 01; hydrocephalus: RR=0.24, 95%CI (0.13, 0.41), P<0.000 01; cerebral infarction: RR=0.27, 95%CI (0.16, 0.45), P<0.000 01]. Only one trial reported the adverse events of lumbar continuous drainage of the cerebrospinal fluid including intracranial infection and intracranial hypotension reaction, while the others did not report the adverse events. ConclusionWith poor quality of the most included trials, insufficient evidence is obtained to support the conclusion that lumbar continuous drainage of the cerebrospinal fluid is safe and effective in the treatment of SAH. Further high-quality RCTs should be carried out to provide more reliable evidences.