A 78-year-old woman presented with fever, severe abdominal pain, and distension. She had been institutionalized for depression and senile dementia. Laboratory examinations disclosed a leucocytosis (WBC:12 500/μL) and elevated levels of serum C-reactive protein (2.8 mEq/L). Diagnosis of acute cecal volvulus was made from a "coffee bean sign" on an abdominal computed tomography and a "beak sign" on a gastrographin enema. An emergent laparotomy confirmed the diagnosis and an ileo-colectomy with primary anastomosis wascarried out. The patient recovered after intensive respiratory care and fluid therapy, and then returned to her former institution. A review of Japanese literature disclosed that:(1) a marked increase of aged patients with mental disability presenting with cecal volvulus, (2) adoption of ileo-colectomy as the standard surgical procedure, and (3) improved survival of the patients, were observed in the last decade.