BACKGROUND: Laparoscopic surgery has potential theoretical advantages over open surgery in reducing the rate of adhesion formation, but very few comparative studies are available to prove this. METHODS: A literature search was performed within Medline and Cochrane databases using the key words: adhesion*, adhesiolysis, laparoscop*, laparotomy, open surgery. Further articles were identified from the reference lists of retrieved literature. Both clinical and experimental studies comparing laparoscopy and laparotomy with regard to adhesion formation were retained. In each article, the rates of adhesion formation were identified or deduced for the operative site, access wound site, and distant sites. RESULTS: Fifteen studies from 1987 to 2001 were identified. Most studies assessed the operative site. Thus, three clinical studies and six experimental ones found fewer adhesions following laparoscopy than laparotomy, while other five experimental studies found similar adhesion rates for the two surgical methods. There were fewer adhesions to trocar wounds than to the laparotomy wounds in seven studies and equal rates of adhesion in one study. The problem of distant adhesions is poorly represented in literature; three studies favored laparoscopy as being followed by fewer adhesions. Because of the important differences between studies with regard to the design, end points, and statistical calculations, a metaanalysis could not be achieved. The conclusion is based on the prevalence of evidence. CONCLUSIONS: All clinical studies and most of the experimental studies found a reduction of adhesion formation after laparoscopic surgery compared to open surgery.