PURPOSE: To evaluate the CT and US features of the colonic villous tumors. MATERIALS AND METHODS: We retrospectively reviewed the CT findings of 11 cases with histologically proved colonic villous tumor. CT parameters evaluated were morphological appearances and enhancing pattern (size, shape, margin, presence or absence of fronds, bowel wall thickening). CT features of six cases with malignant change were compared with five tumors without malignant change. US features available in 10 patients were also analyzed. RESULTS: On CT, thetumors showed irregular margin(n=9), presence of fronds(n=6), lobulated shape(n=11), with pericolonic invasion(n=1). Six cases with malignant change were larger(mean, 6.8cm in diameter) than those without malignant change(mean, 3.3 cm). US features in 10 cases were intraluminal mass(n=5), colonic wall thickening(n=5), with variable echogenicity. CONCLUSIONS: Colonic villous tumor appeared as a nonspecific mass on CT and US with adifficulty in distinguishing from colon carcinoma.