Background. Any form of trauma, including surgery, is known to result in oxidative stress. Increased intra-abdominal pressure during pneumoperitoneum and inflation-deflation may cause ischemia reperfusion and, hence, oxidative stress may be greater during laparoscopic surgery. The aim of this study was to systemically review the literature to compare oxidative stress in laparoscopic and open procedures. Methods. A systematic search of the Medline, Pub Med, EMBASE, and Cochrane databases was performed with the following keywords: pneumoperitoneum AND surger$ OR laparoscop$ AND oxida$. The search was limited to articles published between 1980 and August 2010. Results. The initial search identified 197 papers. After review of the abstracts, 17 papers met the inclusion criteria. Six more papers were identified through the reference lists. It was not possible to perform a meta-analysis due to heterogeneity of patient data, patient selection criteria, and diversity of biomarkers used. The majority of studies demonstrated greater immediate oxidative stress after open surgery. There was, however, a paucity of studies comparing open versus laparoscopic surgery with regards to tissue oxidative stress. Conclusion. Laparoscopic surgery seems to produce less systemic oxidative stress. However the effect of pneumoperitoneum on local oxidative stress and tissue hypoxia and its clinical significance need further investigation. (C) 2011 Elsevier Inc. All rights reserved.