We herein present a patient with lipomatosis of the ileum including diverticulosis and volvulus. The patient presented with abdominal pain and vomiting. Preoperatively, we diagnosed lipomatosis with volvulus of the ileum based on the findings of abdominal ultrasonography (US) and computed tomography (CT). During surgery, the dilated ileum had rotated 720 degrees counterclockwise, and was found to contain lipomatosis and multiple diverticula. Although lipomatosis of the small bowel is extremely rare, it does show characteristic US and CT findings, thus making a preoperative diagnosis possible if this disease is included in the differential diagnosis.