Lymphography has been performed in 46 patients with leukemia and the common distinctive features are evaluated. There is a general increase in the size and number of the lymph node. Their outline is well-defined and saucer-shaped and their internal pattern is coarsely dotted. Lymphographically, there is no significant difference between myeloid leukemia and lymphatic leukemia. Sometimes, the lymph nodes in chronic lymphatic leukemia are gigantic and the internal basophilic is frothy (ecumeux) or fantomatique. The internal pattern of the lymph nodes in chronic myeloid leukemia and acute myeloid leukemia presents a similar finding and that in monocytic leukemia, basophilic leukemia and erythroleukemia is not specific. Although there is no pathognomonic finding for each form of leukemia, the leukemic patterns are certainly different from those of normal, inflammatory or metastatic lymph nodes. Lymphography also is useful for the detection of leukemic involvement of the deep-seated lymph nodes, and allows sequential observations or their size changes following therapy. The side effects of lymphography include a transiert fever and pulmonary embolism, but serious untoward reactions are rare. The author experienced 3 patients with clinical signs compatible with pulmonary embolism and 17 cases of fever among 76 cases examined. However, there was no mortality and fever was preventable by intravenous injection of 30 mg of predonisolone. The peripheral blood pictures showed no significant changes. As a systemic reaction iodine anaphylaxy is reported but there is no such drug reaction in the present series.