Computed tomography (CT) was performed in 30 patients with histologically proven lymphoma within 1 week of bipedal lymphangiography to assess the relative sensitivity of each diagnostic modality in defining the location and extent of lymphomatous involvement. In 11 patients, lymphangiography significantly underestimated the volume of the periaortic nodal mass and its cephalad extent. In 13 additional patients, CT defined significant renal hilar, mesenteric, splenic hilar, and splenic pulp extension not visualized by lymphangiography. Sequential CT scans performed in five patients proved an excellent way to follow therapeutic response. CT scans were also performed in 26 patients with nonlymphomatous intraabdominal malignancy within a week of lymphangiography. It was of value in staging patients with carcinoma of the testis but was not overly helpful in patients with carcinoma of the ovary or pancreas.