Background Studies in traumatic encephalopathy first led to the insight that the damage seen was not just due to direct consequences of the primary injury. A significant, and potentially preventable, contribution to the overall morbidity arose from secondary hypoxic-ischaemic damage. Brain swelling accompanied by raised intracranial pressure (ICP) resulted in inadequate cerebral perfusion with well-oxygenated blood. Detection of raised ICP could be useful in alerting clinicians to the need to improve cerebral perfusion, with consequent reductions in brain injury. Objectives To determine whether routine ICP monitoring in all acute cases of severe coma reduces the risk of all-cause mortality or severe disability at final follow-up. Search strategy We searched the Cochrane Injuries Group's Specialised Register (searched 7 April 2009), CENTRAL (The Cochrane Library 2009, Issue 1), MEDLINE 1950 to March week 4 2009, EMBASE 1980 to week 14 March 2009, CINAHL 1982 to March 2009, ISI Web of Science: Science Citation Index Expanded (SCI-EXPANDED) 1970 to March 2009, Conference Proceedings Citation Index-Science (CPCI-S) 1990 to March 2009, PubMed (searched 7 April 2009, limit; added in last 6 months). The searches were last updated in April 2009. Selection criteria All randomised controlled studies of real-time ICP monitoring by invasive or semi-invasive means in acute coma (traumatic or non-traumatic aetiology) versus no ICP monitoring (that is, clinical assessment of ICP). Data collection and analysis Primary outcome measures were all-cause mortality and severe disability at the end of the follow-up period. Main results No studies meeting the selection criteria have been identified to date. Authors' conclusions There are no data from randomised controlled trials that can clarify the role of ICP monitoring in acute coma.