The computed tomographic findings of 30 mesenteric masses are presented. To delineate the mesentery accurately, oral contrast material must fill the entire small bowel. Of the masses, 23 were secondary to non-Hodgkin's lymphoma. These masses were irregular in shape and homogeneous in their tissue attentuation. Two of the 23 had a normal lymphangiogram in the upper paraaortic area. Both lymphangiography and CT were necessary to define the extent of disease in such patients. The six mesenteric metastases were irregular in shape. Four of these had areas of decreased attentuation eccentrically located within the mass which may be secondary to necrosis. One mesenteric cyst had a circular shape with smooth, sharp borders, and a centrally located area of decreased attenuation.