Sedation is often used to improve comfort, reduce anxiety and stress and to facilitate nursing care of critically ill patients in the intensive care unit. This meta-analysis examined the benefits and risks of daily sedation interruption in critically ill adult patients. A total of five randomised controlled trials, comparing daily sedation interruption with no interruption in 699 critically ill patients, from the Cochrane controlled trials register, Embase and MEDLINE databases (1966 to April 2010) were identified and subject to meta-analysis. With the limited data available, daily sedation interruption was not associated with a significant reduction in duration of mechanical ventilation, length of intensive care unit and hospital stay, or mortality. Daily sedation interruption was associated with a reduced risk of requiring tracheostomy (odds ratio 0.57, 95% confidence interval 0.35 to 0.92, P = 0.02; F = 3%) but not an increased risk of removal of the endotracheal tube by the patients (odds ratio 1.3, 95% confidence interval 0.41 to 4.10, P = 0.65; F = 49%). The current evidence suggests that daily sedation interruption appears to be safe, but the significant heterogeneity and small sample sizes of the existing studies suggest that large randomised controlled studies with long-term survival follow-up are needed before daily sedation interruption can be recommended as a standard sedation practice for critically ill adult patients.