Critically ill patients commonly develop hyperglycemia. It remains unclear, however, to what extent correcting hyperglycemia will benefit these patients. We performed this meta-analysis to evaluate the benefits and risks of intensive glucose control versus conventional glucose control in critically ill adult patients.A systematic literature search of MEDLINE, PubMed, and Cochrane databases (until June 2011) was conducted using specific search terms. Randomized controlled trials that compared intensive glucose control with a target glucose goal <6.1 mmol/l (110 mg/dl) to conventional glucose control in adult intensive care patients were included. The random-effect model was used to estimate the pooled risk ratio of the two treatment arms.Twenty two studies that randomized 13,978 participants were included in the meta-analysis. Overall, intensive glucose control did not reduce the short-term mortality (RR=1.02, 95% CI: 0.95-1.10, p=0.51), 90 day or 180 day mortality (RR=1.06, 95% CI: 0.99-1.13, p=0.08), sepsis (RR=0.96, 95% CI: 0.83-1.12, p=0.59) or new need for dialysis (RR=0.96, 95% CI: 0.83-1.11, p=0.57). The incidence of hypoglycemia was significantly higher in intensive glucose control group compared with conventional glucose control group (RR=5.01, 95% CI: 3.45-7.28, p<0.00001).This meta-analysis found that intensive glucose control in critically ill adults did not reduce mortality but is associated with a significantly increased risk of hypoglycemia.