Treitz's hernia is the eponymous name for a paraduodenal hernia. These are rare hernias that arise in the potential spaces and folds of the posterior parietal peritoneum adjacent to the ligament of Treitz. Presentation may be acute with small bowel obstruction or bowel ischaemia, or with chronic intermittent abdominal pain. Treatment is by surgery, due to the high (50%) lifetime risk of obstruction. Here, we present two cases from our own institution and review the literature regarding the embryology, anatomy, cross-sectional imaging and surgery of these fascinating hernias.