BACKGROUND Reduction en-masse of an inguinal hernia is a very uncommon condition in which a hernia sac migrates into the preperitoneal space containing an incarcerated bowel loop. CASE REPORT A 76-year-old male patient with a 4-year history of reducible left inguinal hernia complained of abdominal pain for 2 h before admission. Contrast-enhanced computed tomographic (CT) images revealed a small bowel obstruction with dilatation from the distal jejunum to the proximal ileum and a closed-loop obstruction showing a 6.2-cm oval-shaped sac in the preperitoneal space. CONCLUSIONS Diagnosis of reduction en-masse of inguinal hernia is often challenging due to the infrequency of its occurrence, although it has specific CT findings. The present case report suggests that clinical and radiological awareness are very important for accurate diagnosis and management in patients with reduction en-masse of an inguinal hernia.