We report herein a unique cause of duodenal obstruction secondary to expansion of an abdominal aortic aneurysm in a 75-year-old man with congenital malrotation of the intestines. The duodenum was found to be compressed between the abdominal aortic aneurysm inferiorly and the peritoneal band superiorly. The patient underwent uncomplicated lysis of peritoneal bands relieving the duodenal obstruction, followed by repair of the abdominal aortic aneurysm.