Lymphangiography (LAG) and abdominal computed tomography (CT) were performed on 13 intravenous drug (heroin) abusers with persistent generalized lymphadenopathy (PGL). All 12 LAG performed were abnormal with a repetitive pattern of diffuse abnormalities of internal structures with small filling defects of both pelvic and abdominal lymph nodes. In 12/13 (92%) of the patients, lymphadenopathy was evidenced by CT scan as well. Retroperitoneal lymph nodes were always abnormal, mesenteric and pelvic nodes in 7 patients each. In 9/13 (69%) of the patients, the spleen was found to be moderately enlarged. The LAG films of our first 2 patients referred to us with an erroneous histologic diagnosis of malignant lymphoma were read to be consistent with involvement by lymphoma. Considering that patients with PGL are at risk for transformation to malignant lymphoma, the LAG and CT findings of PGL should be kept in mind when transformation to malignant lymphoma occurs and staging is performed.