Malignant coloenteric fistula is a rare complication of colon cancer. Colon carcinoma is the most common etiology of this entity. Clinical features are diarrhea, weight loss, anemia and feculent vomiting. The diagnosis is most often made by barium enema examination. The primal therapy is operation. We present a case of a 51-year old male in whom a coloenteric fistula caused by transverse colonic carcinoma. He complained of abdominal pain, diarrhea and dizziness. UGI series demonstrated a fistulous track between colon and small bowel. On abdominal CT examination, a mass involving hepatic flexure of colon with a fistulous tract and metastatic nodules in right lobe of liver were found. Colonoscopy revealed a circumferential mass and the orifice of the fistula. The patient refused operation and expired one month after discharge.