This meta-analysis examined the benefits of using remifentanil as a sedative agent in critically ill patients. A total of 11 randomised controlled trials, comparing remifentanil with another opioid or hypnotic agent in 1067 critically ill adult patients, were identified from the Cochrane controlled trials register and EMBASE and MEDLINE databases, and subjected to meta-analysis. Remifentanil was associated with a reduction in the time to tracheal extubation after cessation of sedation (weighted-mean-difference −2.04 h (95% CI −0.39 to −3.69 h); p = 0.02). Remifentanil was, however, not associated with a significant reduction in mortality (relative risk 1.01 (95% CI 0.67–1.52); p = 0.96), duration of mechanical ventilation, length of intensive care unit stay, and risk of agitation (relative risk 1.08 (95% CI 0.64–1.82); p = 0.77) when compared to an alternative sedative or analgesic agent. The current evidence does not support the routine use of remifentanil as a sedative agent in critically ill adult patients.