Kaposi's sarcoma (KS) is the most common AIDS-associated neoplasm. It involves the gastrointestinal tract, skin and lymph nodes with about equal frequency. However, most cases of gastrointestinal KS are clinically silent and found incidentally. We report the case of a 31-year-old homosexual man who developed intussusception in association with a primary ileal KS. He was admitted due to abdominal pain lasting 2 hours. Flat abdominal roentgenogram revealed small bowel ileus in the central abdomen. Abdominal sonography and computerized tomography revealed an intraluminal soft tissue mass in the small intestine with an intussusception. Exploratory laparotomy found an ileal tumor mass 90 cm proximal to the ileocecal valve. Pathologic examination of the resected intestine showed KS. HIV-1 infection was confirmed by Western blot. The CD4 T-cell count was 59/mm3. In conclusion, intussusception by enteric KS may present as the initial AIDS-associated neoplasm in patients with HIV infection.