Background: Clinical studies lend to support the benefit of the use of enteral nutrition rather than parenteral nutrition. Aim: To substantiate these results further, systematic review and meta-analysis of randomized controlled trials of enteral nutrition compared with parenteral nutrition was conducted. Methods: A search was conducted on Medline, Web of Science (January 1979 to October 2003), and the Cochrane Library (2003 Issue 4) electronic databases for the English language literature and bibliographic reviews. Data were abstracted in duplicate, independently. Main outcome measures are anastomotic leak, wound infection, pneumonia, intra-abdominal abscess, infection of any type, and mortality. Results: Sixteen trials, which included 1,584 patients, met the inclusion criteria. Enteral nutrition was not associated with a reduction in pneumonia (pooled odds ratio [OR] 0.84, 95% confidence interval [CI] 0.53-1.35, P=0.469), wound infection (pooled OR 0.79, 95% CI 0.51-1.25, P=0.319), intra-abdominal abscess (pooled OR 0.67, 95% CI 0.36-1.26, P=0.216), anastomotic leak (pooled OR 0.67, 95% CI 0.42-1.05, P=0.08), and mortality (pooled OR 0.71, 95% CI 0.39-1.30, P=0.262). Enteral nutrition was significantly associated a reduction in infection of any type (pooled OR 0.64, 95% CI 0.47-0.88, P=0.006). There was no heterogeneity. Conclusions: Enteral nutrition significantly reduces infection of any type compared with parenteral nutrition. But there seems to be no clear benefit for other complications.