Systematic review of natural orifice transluminal endoscopy surgery (NOTES) for intrabdominal surgeryBackground: NOTES allows to perform entire traditional surgical procedures through a natural orifice. Aim: To evaluate models, techniques, outcomes, pitfalls, and applicability to the clinical setting of NOTES for intra abdominal surgery. Material and Methods: Systematic review of the literature. Studies were identified searching MEDLINE, EMBASE, CINAHL, Current Contents, Cochrane Library, Entrez PubMed, Clinical Trials Database from 2000 to 2008. Studies indentified in October 2008, were included if they were performed in live human subjects. Results: Of the studies included for review, most were experimental studies conducted in animals. Thus, the evidence base was very limited. Although intra-abdominal access could be achieved reliably via oral, anal, or urethral orifices, the optimal access route and method could not be established. Closure of viscerotomies could not be achieved reliably in all cases and the risk of peritoneal infection was not adequately evaluated. Although the majority of interventions could be performed in animals using NOTES, a number of technical problems were encountered that need to be resolved. Conclusions: NOTES is still in early stages of development and more robust technologies will be needed to achieve reliable closure and overcome technical challenges. Well-managed human studies need to be conducted to determine the safety and efficacy of NOTES in a clinical setting.