Adult intussusception is a rare cause of acute abdomen in adults but is relatively common in children younger than 3 years of age. In contrast to pediatric cases, most adult intussusceptions are associated with an identifiable lead-point lesion. We report the case of a 51-year-old woman who presented with a one-day history of upper and right lower abdominal pain. Comprehensive evaluation revealed ileocecal intussusception with a leading tumor. The patient subsequently underwent radical right hemicolectomy. Pathological examination confirmed that the ileocecal intussusception was secondary to ileal diffuse large B-cell lymphoma.