A 63-year-old male patient suddenly suffered right lower abdominal pain. The patient had tenderness and rebound tenderness at the right lower abdomen. Marked small bowel dilatation and an intestinal obstruction were evident upon abdominal X-ray and abdominal computed tomography (CT) imaging. CT imaging also revealed a dilated small bowel cluster in a wrapped round shape in the right lower abdomen. The cecum and the ascending colon were displaced inward. Strangulation in the ileocecal region was suspected, and emergency surgery was performed. A part of the small bowel was incarcerated within the retrocecal recess, and the intestinal tract was strangulated in the hernia orifice, by which paracecal hernia was diagnosed. The strangulated intestinal tract was repositioned, and the orifice to the hernia was closed. Paracecal hernia is a rare disease; an internal hernia should always be considered in patients with ileus without a history of surgery.