Tumors of the small intestine are rare. The frequency of benign tumors is lower than that of malignant ones. We report a case of large leiomyoma of the ileum. A 72-year-old male patient with an abdominal mass was referred here from a urologist for treatment. He complained of pollakiuria. He didn't notice his own abdominal mass. Echogram and computed tomography showed a large tumor in the peritoneal cavity. The tumor arising from the ileum was found at the time of operation. Resected tumor was 14×8 cm in size and 7 cm in height. The weight of it was 600 gm. Histologically the tumor was leiomyoma.