Internal hernias, protrusion of abdominal viscera into an intraperitoneal fossa, are uncommon causes of bowel obstruction, and preoperative diagnoses are difficult. We report a rare case of a 47-year-old female with strangulated small bowel obstruction secondary to an intramesosigmoid hernia preoperative diagnosis by multi-detector row computed tomography. We highlight the preoperatively diagnosed value and findings of MDCT in intramesosigmoid hernia.