The authors propose to conduct, in a systematic manner, lymphography and ultrasonography examinations before treatment of 75 cases of non-Hodgkin's lymphoma. The latter investigation enables examination of the upper part of the retroperitoneal space, and the detection of coeliomesenteric adenopathies, or possible lesions in the liver, spleen, and kidneys. The surveillance of most patients during treatment is possible with ultrasonography, if marked lipiodol resorption has occurred. Though this procedure is easy to conduct in all radiological departments, it does not have the same sensitivity as lymphography associated with computed tomography.