The clinical significance of lymphography is discussed through experiences of 34 cases of malignant lymphomas and allied diseases; 7 cases of lymphosarcoma, 5 cases of reticulosarcoma, 11 cases of Hodgkin's diseases 5 cases of giant follicular lymphoma, 4 cases of unclassifiable malignant lymphoma, and 2 cases of macroglobulinemia. 1) Lymphosarcoma The enlarged lymph nodes in lymphosarcoma are well defined but there may be partial filling defects. The internal structures are finely or coarsely reticular. 2) Reticulosarcoma The lymphogram also reveals a distinct margin. The internal architecture appears like honeycomb, finely dotted or coarsely reticular and often shows diffuse filling defects. 3) Hodgkin's disease The lymph node appearance is characteristic. The border remains distinct but has irregular marginal dotted filling defects, and the internal pattern is coarsely dotted and often shows moth-eaten or punched out filling defects. Sometimes, linear cystic appearance is found. 4) Giant follicular lymphoma The lymphogram of giant follicular lymphoma is not pathognomonic and eventually may present a sarcoma-like appearance. 5) Macroglobulinemia The border remains intact. The internal pattern of the lymph nodes is coarsely dotted or may be later reticular and in some areas follicular filling defects are seen. It may be stated that characteristic lymphographical pictures are recognized for typical cases. But sometimes these findings overlop each other and the x-ray findings are not pathognomonic. Therefore, it is difficult to make an accurate diagnosis on the type of malignant lymphomas. However, we can differentiate those from the inflammatory and metastatic patterns. Lymphography in malignant lymphomas and allied diseases is very important for the diagnosis of the localization and spread of the disease. Especially, in the abdominal type, lymphogram is of definitive value. Furthermore, this method is useful for the search of progression and understanding of therapeutic effects.