SummaryAfter having described the technique of lymphography, the author details the normal radiological anatomy of the retroperitoneal lymph system.In lymphcedema the presence of specific lymphangiography patterns allow the differentiation between primary hypoplasia or malformation of the lymph vessels from secondary fibr osis or stasisLymphography is of particular interest in the identification of tumors of the lymph vessels and in the detection of the origin of chylous effusions.In the second part, the pathology of the lymph nodes is studied. The«typical>lymphographie features of metastasis and of several classes of lymphomas arc illustrated. Often however it appears to be impossible to differentiate these pathological processes since unspecific changes are likely to occur. Moreover the radiological aspect of complete lymph node destruction is common to the late evolution-stage of all of these diseases.Thus lymphography permits the study of a region of the human anatomy which is very difficult to examine; in well selected cases important information can be gained from this simple and safe investigation.