Duodenal obstruction caused by abdominal aortic aneurysm (AAA), i.e. "aortoduodenal syndrome," first described by Osler in 1905 is a rare clinical entity, with only several dozens of cases reported in the literature. In the present paper, we systematically searched literature and reviewed them. Databases including MEDLINE and EMBASE were searched from January 1981 to April 2014 using Web-based search engines (PubMed and OVID). Eighteen papers reported 21 cases with aortoduodenal syndrome. Mean age of patients was 74.5±8.4 years, 71.4% of patients were men, and mean AAA diameter was 7.2±2.1 cm. We also discussed confusion between aortoduodenal syndrome and "superior mesenteric artery syndrome" associated with AAA.