Kaposi sarcoma-associated herpesvirus (KSHV), also known as human herpesvirus 8 (HHV8), has been identified in all four forms of Kaposi's sarcoma (classic, endemic, HIV-associated and iatrogenic). We report the rare case of an intestinal (small intestine and rectosigmoid) Kaposi's sarcoma in a 62-year-old HIV-negative man with ulcerative colitis. This patient was receiving immunosuppressive therapy with steroids and azathioprine. To date, the causative role of KSHV/HHV8 in the pathophysiology of Kaposi's sarcoma associated with ulcerative colitis has only been proven for cutaneous lesions but not for intestinal lesions of Kaposi's sarcoma. We report for the first time, the expression of HHV8 (by using immunohistochemistry) in colonic Kaposi's sarcoma in a patient with an ulcerative colitis-related tumor. The patient underwent a total proctocolectomy. At laparotomy, numerous Kaposi's sarcoma lesions were found in the small intestine, which were left in situ. Forty months after surgery and following withdrawal of immunosuppressive therapy, the patient had no evidence of any disease and a normal abdominal and thoracic CT scan. Cases of colorectal Kaposi's sarcoma complicating inflammatory bowel disease should be managed with a conservative approach and discontinuation of the immunosuppressive treatment. However, discontinuation of the immunosuppression is not always possible and in those cases chemotherapy may be indicated.