Small bowel volvulus complicating incomplete common mesentery corresponds to an arrest in the 180° rotation of the primitive intestinal loop. The root of the mesentery is very short and the entire small intestine is pedunculated on the superior mesenteric artery. This situation carries a very high risk of small bowel volvulus and entero-mesenteric infarction. Acute volvulus requires emergency surgery; imaging should not delay surgical management. The surgical procedure consists of untwisting the volvulus (anticlockwise) and assessing the viability of the intestine. The intestine is stored in the position of complete common mesentery: coetus in the left iliac fossa. We report the observation of a 24-year-old patient admitted for small bowel volvulus on incomplete common mesentery, operated on as an emergency with a favourable postoperative outcome.